Risk Factors for Postural and Functional Balance Impairment in Patients with Chronic Obstructive Pulmonary Disease

Exploring Balance Impairment and Determinants in Chronic Obstructive Pulmonary Disease: A Comparative Study with Healthy Subjects

Background: Many pulmonary and extrapulmonary factors may impair balance in patients with chronic obstructive pulmonary disease (COPD), but the determinants of this impairment are still debated. The primary aim was to compare both balance-related and independent variables that may affect balance with healthy subjects. The secondary aim was to investigate the potential determinants of balance in patients with COPD. Methods: This comparative study recruited 23 patients with COPD and 23 age- and comorbidity-matched healthy subjects. Participants were assessed regarding demographic and clinical data, "Postural Stability Test" (PST), "Limits of Stability Test" (LOST), "Clinical Test of Sensory Integration of Balance" (CTSIB), pulmonary function, respiratory and peripheral muscle strength, functional capacity, and cognitive function. Results: There were significant differences in all outcome measures assessing balance, pulmonary function, respiratory muscle strength, peripheral muscle strength, and functional capacity, but not cognitive function, in the COPD group compared to the healthy group (p < 0.05). The PST had a significant and strong correlation with maximal inspiratory pressure (MIP) (r = -0.630, p = 0.001) and a significant and moderate correlation with m. quadriceps strength and 6 min walk test (6MWT) distance (r = -0.472, p = 0.023; r = -0.496, p = 0.016; respectively). MIP, m. quadriceps strength, and 6MWT distance were independent predictors to explain the PST with an R2 = 0.336 (p = 0.004). Conclusions: The present study revealed that balance is impaired in adults with COPD, even if compared with age- and comorbidity-matched healthy subjects. Assessing and improving balance and its determinants, inspiratory and peripheral muscle strength, and functional capacity may be important for fall prevention and disease management in patients with COPD.

Gait differences between COPD and healthy controls: systematic review and meta-analysis

BACKGROUND

Despite the importance of gait as a determinant of falls, disability and mortality in older people, understanding of gait impairment in COPD is limited. This study aimed to identify differences in gait characteristics during supervised walking tests between people with COPD and healthy controls.

METHODS

We searched 11 electronic databases, supplemented by Google Scholar searches and manual collation of references, in November 2019 and updated the search in July 2021. Record screening and information extraction were performed independently by one reviewer and checked for accuracy by a second. Meta-analyses were performed in studies not considered at a high risk of bias.

RESULTS

Searches yielded 21 085 unique records, of which 25 were included in the systematic review (including 1015 people with COPD and 2229 healthy controls). Gait speed was assessed in 17 studies (usual speed: 12; fast speed: three; both speeds: two), step length in nine, step duration in seven, cadence in six, and step width in five. Five studies were considered at a high risk of bias. Low-quality evidence indicated that people with COPD walk more slowly than healthy controls at their usual speed (mean difference (MD) -19 cm·s-1, 95% CI -28 to -11 cm·s-1) and at a fast speed (MD -30 cm·s-1, 95% CI -47 to -13 cm·s-1). Alterations in other gait characteristics were not statistically significant.

CONCLUSION

Low-quality evidence shows that people with COPD walk more slowly than healthy controls, which could contribute to an increased falls risk. The evidence for alterations in spatial and temporal components of gait was inconclusive. Gait impairment appears to be an important but understudied area in COPD.

Impairment and characteristics of postural control sub-components in people with COPD: a scoping review

PURPOSE

Impairment of postural control is common in people with COPD. However, the precise characteristics of this alteration are not clearly known. The "Systems Framework for Postural Control" which define postural control sub-components, represents an interesting tool to explore this field. The main aim of this review was to identify which postural control sub-components are impaired in people with COPD and to summarise characteristics for each sub-component. A secondary aim was to precise the relation between postural control and activities of daily living (ADL).

MATERIALS AND METHODS

A scoping review was conducted, according to the JBI methodology. Medline, Cochrane Library, Scielo, Google Scholar, OpenGrey, and HAL were searched from inception to May 2022. The search was performed in English and French.

RESULTS

Eighty-nine articles were included. There was evidence of a potential impairment for most of the postural control sub-components. Characteristics of every sub-component alteration were heterogeneous. Reduced postural control could be associated with difficulties in ADL.

CONCLUSIONS

People with COPD may have impairment in a wide range of postural control sub-components. Further research is needed to clarify if a common pattern of modification exits for this alteration and to precise the link with ADL.Implications for rehabilitationImpairment of postural control is a common extra-respiratory manifestation in people with COPD and so clinicians must include it in their clinical reasoning.Numerous postural control sub-components could be altered in people with COPD, suggesting that postural control assessment must be holistic.This scoping review shows that characteristics of postural control impairment are varied and that there may be no common pattern at the COPD population level.The relationship between impaired postural control and activities of daily living remains unclear, but clinicians should be alert to potential negative interactions between these two areas.

Impact of cognitive capacity on physical performance in chronic obstructive pulmonary disease patients: A scoping review

Background: Chronic obstructive pulmonary disease (COPD) is often accompanied by impaired cognitive and physical function. However, the role of cognitive function on motor control and purposeful movement is not well studied. The aim of the review was to determine the impact of cognition on physical performance in COPD. Methods: Scoping review methods were performed including searches of the databases: MEDLINE, EMBASE, Cochrane Systematic Reviews, Cochrane (CENTRAL), APA PsycINFO, and CINAHL. Two reviewers independently assessed articles for inclusion, data abstraction, and quality assessment. Results: Of 11,252 identified articles, 44 met the inclusion criteria. The review included 5743 individuals with COPD (68% male) with the forced expiratory volume in one second range of 24-69% predicted. Cognitive scores correlated with strength, balance, and hand dexterity, while 6-min walk distance (n = 9) was usually similar among COPD patients with and without cognitive impairment. In 2 reports, regression analyses showed that delayed recall and the trail making test were associated with balance and handgrip strength, respectively. Dual task studies (n = 5) reported impaired balance or gait in COPD patients compared to healthy adults. Cognitive or physical Interventions (n = 20) showed variable improvements in cognition and exercise capacity. Conclusions: Cognition in COPD appears to be more related to balance, hand, and dual task function, than exercise capacity.

Updated Perspectives on the Role of Biomechanics in COPD: Considerations for the Clinician

Patients with chronic obstructive pulmonary disease (COPD) demonstrate extra-pulmonary functional decline such as an increased prevalence of falls. Biomechanics offers insight into functional decline by examining mechanics of abnormal movement patterns. This review discusses biomechanics of functional outcomes, muscle mechanics, and breathing mechanics in patients with COPD as well as future directions and clinical perspectives. Patients with COPD demonstrate changes in their postural sway during quiet standing compared to controls, and these deficits are exacerbated when sensory information (eg, eyes closed) is manipulated. If standing balance is disrupted with a perturbation, patients with COPD are slower to return to baseline and their muscle activity is differential from controls. When walking, patients with COPD appear to adopt a gait pattern that may increase stability (eg, shorter and wider steps, decreased gait speed) in addition to altered gait variability. Biomechanical muscle mechanics (ie, tension, extensibility, elasticity, and irritability) alterations with COPD are not well documented, with relatively few articles investigating these properties. On the other hand, dyssynchronous motion of the abdomen and rib cage while breathing is well documented in patients with COPD. Newer biomechanical technologies have allowed for estimation of regional, compartmental, lung volumes during activity such as exercise, as well as respiratory muscle activation during breathing. Future directions of biomechanical analyses in COPD are trending toward wearable sensors, big data, and cloud computing. Each of these offers unique opportunities as well as challenges. Advanced analytics of sensor data can offer insight into the health of a system by quantifying complexity or fluctuations in patterns of movement, as healthy systems demonstrate flexibility and are thus adaptable to changing conditions. Biomechanics may offer clinical utility in prediction of 30-day readmissions, identifying disease severity, and patient monitoring. Biomechanics is complementary to other assessments, capturing what patients do, as well as their capability.

Age and Sex Differences in Balance Outcomes among Individuals with Chronic Obstructive Pulmonary Disease (COPD) at Risk of Falls

No previous research has examined age and sex differences in balance outcomes in individuals with chronic obstructive pulmonary disease (COPD) at risk of falls. A secondary analysis of baseline data from an ongoing trial of fall prevention in COPD was conducted. Age and sex differences were analyzed for the Berg Balance scale (BBS), Balance Evaluation System Test (BEST test) and Activities-specific Balance Confidence Scale (ABC). Overall, 223 individuals with COPD were included. Females had higher balance impairments than males [BBS: mean (SD) = 47 (8) vs. 49 (6) points; BEST test: 73 (16) vs. 80 (16) points], and a lower confidence to perform functional activities [ABC = 66 (21) vs. 77 (19)]. Compared to a younger age (50-65 years) group, age >65 years was moderately associated with poor balance control [BBS (r = - 0.37), BEST test (r = - 0.33)] and weakly with the ABC scale (r = - 0.13). After controlling for the effect of balance risk factors, age, baseline dyspnea index (BDI), and the 6-min walk test (6-MWT) explained 38% of the variability in the BBS; age, sex, BDI, and 6-MWT explained 40% of the variability in the BEST test; And BDI and the 6-MWT explained 44% of the variability in the ABC scale. This study highlights age and sex differences in balance outcomes among individuals with COPD at risk of falls. Recognition of these differences has implications for pulmonary rehabilitation and fall prevention in COPD, particularly among females and older adults.

Balance impairment and lower limbs strength in patients with COPD who fell in the previous year

Fall-related causes in patients with COPD might be associated to functional balance impairments and greater disease severity. We aimed to evaluate the reasons for falls in patients with COPD who had presented any fall during the previous year. This is a cross-sectional study. All COPD's GOLD classifications (mild, moderate, severe, and very severe) patients were recruited. In order to participate, patients ought to be clinically stable and without any exacerbation within 30 days prior to study entry. History of falls was self-reported by patients through an interview. Pre and post bronchodilator (salbutamol 400 μg) spirometry was performed. All patients accomplished postural balance tests such as the Berg Balance Scale, Falls Efficacy Scale-International, Time up and Go, Functional Reach test, Tinetti test and Chalder Scale; furthermore, lower limbs muscle strength (muscle dynamometry) and the COPD Assessment Test (CAT) were assessed. Ninety-six patients with COPD were evaluated and divided into two groups stratified according to any positive history of falls in the previous year. Patients with COPD who had any fall in the previous year presented older age (p=0.01), higher BMI (p=0.04) and worse pulmonary function than those who did not fall. The risk of falls was increased in patients with lower muscle strength in the lower limbs (OR 2.9, CI 95%;1.6 to 3.9), age greater than 65 years (OR 2.7, CI 95%;1.3 to 3.4), BMI greater than 28.8 kg/m2 (OR 3.2, CI 95%;1.1 to 5.6), very severe airway obstruction (OR 3.9, CI 95%;2.2 to 3.9) and fatigue (OR 3.2, CI 95%;1.5 to 5.3). Impaired body balance, reduced lower limb strength, disease severity, presence of fatigue and elevated BMI are important factors for falls in patients with COPD.

Gait and functional balance in non-CF bronchiectasis

BACKGROUND

The decline in ambulatory activities and negative alterations in gait characteristics may impair balance and increase fall risk in obstructive lung diseases. Few studies have evaluated balance and gait parameters in individuals with bronchiectasis.

PURPOSE

This study aimed to compare the gait parameters and functional balance in individuals with non-cystic fibrosis (CF) bronchiectasis and healthy subjects.

METHODS

This cross-sectional and retrospective study analyzed data from 22 individuals with non-CF bronchiectasis and 32 healthy controls recorded between July 2019 and July 2020. Functional balance was assessed using the Timed Up and Go (TUG) test. Gait parameters were evaluated using the Biodex Gait Trainer. Step cycle (s), gait speed (m/s), the number of steps per minute, and ambulation index were measured for 6 min.

Results The TUG time (s) was significantly longer (p = .019, effect size = 0.66), and gait speed (m/s) (p ˂ 0.001, effect size = 2.47), step cycle (s) (p ˂ 0.001, effect size = 2.23), and ambulation index (p ˂ 0.001, effect size = 2.56) were significantly reduced in individuals with non-CF bronchiectasis compared with healthy controls.

CONCLUSION

Non-CF bronchiectasis is related to unfavorable changes in gait characteristics, such as slower gait speed and the decreased average step cycle. In addition, impairment in functional balance and mobility exists in a small percentage of adults with non-CF bronchiectasis. In comprehensive pulmonary rehabilitation, balance and gait evaluations should be included to prevent falls in adults with non-CF bronchiectasis.

Disturbances in branched-chain amino acid profile and poor daily functioning in mildly depressed chronic obstructive pulmonary disease patients

BACKGROUND

Depression is one of the most common and untreated comorbidities in chronic obstructive pulmonary disease (COPD), and is associated with poor health outcomes (e.g. increased hospitalization/exacerbation rates). Although metabolic disturbances have been suggested in depressed non-diseased conditions, comprehensive metabolic phenotyping has never been conducted in those with COPD. We examined whether depressed COPD patients have certain clinical/functional features and exhibit a specific amino acid phenotype which may guide the development of targeted (nutritional) therapies.

METHODS

Seventy-eight outpatients with moderate to severe COPD (GOLD II-IV) were stratified based on presence of depression using a validated questionnaire. Lung function, disease history, habitual physical activity and protein intake, body composition, cognitive and physical performance, and quality of life were measured. Comprehensive metabolic flux analysis was conducted by pulse stable amino acid isotope administration. We obtained blood samples to measure postabsorptive kinetics (production and clearance rates) and plasma concentrations of amino acids by LC-MS/MS. Data are expressed as mean [95% CI]. Stats were done by graphpad Prism 9.1.0. ɑ < 0.05.

RESULTS

The COPD depressed (CD, n = 27) patients on average had mild depression, were obese (BMI: 31.7 [28.4, 34.9] kg/m2), and were characterized by shorter 6-min walk distance (P = 0.055), physical inactivity (P = 0.03), and poor quality of life (P = 0.01) compared to the non-depressed COPD (CN, n = 51) group. Lung function, disease history, body composition, cognitive performance, and daily protein intake were not different between the groups. In the CD group, plasma branched chain amino acid concentration (BCAA) was lower (P = 0.02), whereas leucine (P = 0.01) and phenylalanine (P = 0.003) clearance rates were higher. Reduced values were found for tyrosine plasma concentration (P = 0.005) even after adjustment for the large neutral amino acid concentration (= sum BCAA, tyrosine, phenylalanine and tryptophan) as a marker of dopamine synthesis (P = 0.048).

CONCLUSION

Mild depression in COPD is associated with poor daily performance and quality of life, and a set of metabolic changes in depressed COPD that include perturbation of large neutral amino acids, specifically the BCAAs. Trial registration clinicaltrials.gov: NCT01787682, 11 February 2013-Retrospectively registered; NCT02770092, 12 May 2016-Retrospectively registered; NCT02780219, 23 May 2016-Retrospectively registered; NCT03796455, 8 January 2019-Retrospectively registered.

Impact of chronic obstructive pulmonary disease on passive viscoelastic components of the musculoarticular system

Chronic obstructive pulmonary disease (COPD) produces skeletal muscle atrophy and weakness, leading to impairments of exercise performance. The mechanical work needed for movement execution is also provided by the passive tension developed by musculoarticular connective tissue. To verify whether COPD affects this component, the passive viscoelastic properties of the knee joint were evaluated in 11 patients with COPD and in 11 healthy individuals. The levels of stiffness and viscosity were assessed by means of the pendulum test, consisting in a series of passive leg oscillations. In addition, to explore the contribution of passive tension in the mechanical output of a simple motor task, voluntary leg flexion-extension movements were performed. Patients with COPD showed a statistically significant reduction in stiffness and viscosity compared to controls. Voluntary execution of flexion-extension movements revealed that the electromyographic activity of the Rectus Femoris and Biceps Femoris was lower in patients than in controls, and the low viscoelastic tension in the patients conditioned the performance of active movements. These results provide novel insights on the mechanism responsible for the movement impairments associated with COPD.

Static and dynamic balance impairment and relationship with disease-related factors in patients with chronic obstructive pulmonary disease : A cross-sectional study

BACKGROUND

Disease and aging-related factors may predispose chronic obstructive pulmonary disease (COPD) patients to impaired balance, although the underlying determinants of impaired balance in COPD patients are still unknown. The purpose of this study was to identify the determinants of impaired balance in COPD patients. Also, we aimed to determine which balance measures (clinical or laboratory tests) are more indicative in determining balance impairment in these patients.

METHODS

This cross-sectional study recruited 24 patients with moderate to severe COPD and 24 age-matched healthy subjects. Participants were evaluated regarding demographic and clinical data, previous falls history, lower limb muscle strength, exercise capacity, physical activity and balance level.

RESULTS

COPD patients exhibited significantly a longer test duration on timed up and go test, a higher sway index on the postural stability and lower directional control score on the limit of stability of Biodex balance system (all, p < 0.001) compared to healthy controls, whereas there was no difference in Berg balance scale score between groups (p > 0.05). Balance impairment of the patient group was significantly associated with nonpulmonary conditions, such as physical activity level, exercise capacity, lower limb muscle strength, and with fall history. Also, COPD patients represented significantly lower physical activity level and exercise capacity, weaker lower limb muscle strength than healthy controls (all, p < 0.001).

CONCLUSIONS

Patients with moderate to severe COPD exhibit apparently important reductions in balance control that is directly associated with nonpulmonary consequences and fall history. These results may be extremely important to fall prevention and to guide the development of interventions for this population.