Priscila Robles

Measurement of peripheral muscle strength in individuals with chronic obstructive pulmonary disease: a systematic review.

PURPOSE: Reduced maximal, peripheral muscle strength is associated with exercise intolerance in patients with chronic obstructive pulmonary disease (COPD). Therefore, it is important to accurately evaluate muscle strength to identify patients with muscle weakness and to prescribe adequate loads for resistance training. The objective here was to systematically identify and summarize the literature on measurement of peripheral muscle strength in individuals with COPD and to make recommendations for strength testing in clinical and research settings. METHODS: A literature search was conducted of electronic databases between 1999 and 2009 of all English language articles utilizing muscle strength measurements. RESULTS: The search resulted in retrieval of 178 articles, of which 66 were reviewed. Isometric muscle strength was measured using handgrip (n = 30), strain gauge (n = 15), computerized dynamometer (n = 13), magnetic stimulation (n = 8), handheld dynamometer (n = 6), or manual testing (n = 3). Isotonic muscle strength was measured using a hydraulic system (n = 3) or 1-repetition maximum (n = 9), and isokinetic muscle strength was measured using computerized dynamometer (n = 16). Methodological issues such as limb position, number of trials, subject familiarization, test instructions, rest periods, and muscle group tested were all identified as important variables to consider when developing a strength-testing protocol. CONCLUSION: Muscle strength has been measured in people with COPD using similar methods as in other clinical populations. Each method presents advantages and disadvantages that need to be considered when selecting the most relevant measure. Standardization of the test procedures is essential in both clinical and research settings to obtain valid and reliable measurements of muscle strength.

Measurement of Activities of Daily Living in Patients With COPD: A Systematic Review

BACKGROUND The objectives of this systematic review were to synthesize the literature on measures of activities of daily living (ADLs) that have been used in individuals with COPD and to provide an overview of the psychometric properties of the identified measures and describe the relationship of the disease-specific instruments with other relevant outcome measures for individuals with COPD and health-care use. METHODS Studies that included a measure of ADLs in individuals with COPD were identified using electronic and hand searches. Two investigators performed the literature search. One investigator reviewed the study title, abstract, and full text of the articles to determine study eligibility and performed the data extraction and tabulation. In cases of uncertainty, a second reviewer was consulted. RESULTS A total of 679 articles were identified. Of those, 116 met the inclusion criteria. Twenty-seven ADLs instruments were identified, of which 11 instruments were respiratory disease-specific, whereas 16 were generic. Most instruments combined instrumental ADLs (IADLs) with basic ADLs (BADLs). The majority of the instruments were self-reported; only three instruments were performance based. Twenty-one studies assessed psychometric properties of 16 ADLs instruments in patients with COPD. CONCLUSIONS Although several ADLs instruments were identified, psychometric properties have only been reported in a few. Selection of the most appropriate measure should focus on the target construct (BADLs or IADLs or both), type of test (disease-specific vs generic and self-reported vs performance-based), depth of information obtained, and psychometric properties of the instruments. Given the relevance of ADLs to the lives of patients with COPD, its assessment should be more frequently incorporated as a clinical outcome in their management.

Intramuscular Fat Infiltration Contributes to Impaired Muscle Function in COPD.

UNLABELLED Muscle weakness is a prevalent complication in chronic obstructive pulmonary disease (COPD). Atrophy does not fully explain muscle weakness in this population. The recent focus on fat infiltration and its clinical implications in age and diseased muscles are important because it may further explain the extent of declining muscle strength and mobility seen in COPD. PURPOSE The objectives of this study are to quantify fat infiltration (muscle quality) of lower-limb muscles in people with COPD and healthy older adults using magnetic resonance imaging and proton magnetic resonance spectroscopy, and to explore its relationship with muscle strength and walking capacity in COPD. METHODS T1-weighted magnetic resonance imaging and proton magnetic resonance spectroscopy were performed in people with COPD (n = 10) and control subjects (n = 10) matched for age, gender, and body mass index. Maximal cross-sectional area (muscle size), isokinetic and isometric muscle peak torques, and 6-min walk distance were also assessed. RESULTS In addition to muscle atrophy (mean between-group differences of 20% to 25%, P < 0.05), COPD group presented with fatty infiltration in thigh and calf muscles that were significantly greater than what was observed in their healthy counterparts (mean between-group differences of 74% to 89%, P = 0.001). There was a strong inverse correlation between intramuscular fat infiltration, muscle peak torque, and walking distance (r = -0.6 to -0.8, P < 0.001) in this group as opposed to fair-to-moderate correlations between muscle size and the same outcomes (r = 0.4-0.6, P < 0.01). CONCLUSION Poor muscle quality accompanies atrophy in people with COPD. Intramuscular fat infiltration not only appears to have a strong correlation with impaired function but also is more profound than muscle atrophy in this group. Monitoring both muscle size and quality may enable a more comprehensive assessment of exercise programs in COPD.

Gender-associated differences in pulmonary rehabilitation outcomes in people with chronic obstructive pulmonary disease: a systematic review.

PURPOSE: Although there is substantial evidence to support the importance of pulmonary rehabilitation (PR) in the management of chronic obstructive pulmonary disease, there is less evidence for gender-associated differences in the response to PR. The purpose of this review was to systematically identify and synthesize the available literature on whether men and women with chronic obstructive pulmonary disease respond differently to PR. METHODS: A search of 4 electronic databases was conducted (January 1990 to May 2012) for all English language articles where the goal was to assess gender differences in outcomes after PR. RESULTS: Of the 116 articles retrieved, 11 were included. Five studies reported differences between men and women after PR, for the outcomes of dyspnea, health-related quality of life, physical capacity, psychological and functional status, and coping strategies. Six studies reported no difference in response to PR for the same outcomes. No differences in study designs, study quality, participant characteristics, and type and duration of PR programs were observed between studies that showed gender differences and those that did not. CONCLUSION: There was insufficient evidence to support or refute gender-associated differences in PR outcomes. The impact of gender on the outcome of PR and how these differences may affect the delivery of PR programs remains to be defined.

Does limb partitioning and positioning affect acute cardiorespiratory responses during strength exercises in patients with COPD

Cardiorespiratory responses and symptoms in response to endurance exercise in patients with COPD vary with the number and position of involved limbs. Responses to such variations have never been quantified for strength exercises. We therefore assessed acute cardiorespiratory responses during brief bouts of weight lifting exercises.

Do Field Walking Tests Produce Similar Cardiopulmonary Demands to an Incremental Treadmill Test in Obese Individuals With Treated OSA

BACKGROUND Cardiorespiratory fitness, assessed during cardiopulmonary exercise tests by peak oxygen uptake (Vo2pk), is an independent predictor of mortality in obesity. We investigated whether Vo2pk and systemic responses measured during field walking tests were similar to those measured during an incremental treadmill test (ITMT) in obese individuals with treated OSA. METHODS Individuals with treated OSA and a BMI > 30 kg/m2 were recruited. Participants completed an ITMT, two 6-min walk tests (6MWTs), and two incremental shuttle walk tests (ISWTs) on three separate days in a randomized order. Expired gas analysis was performed during all tests. RESULTS The study was completed by 16 patients (nine men) (mean [SD] age, 58 [12] y; BMI, 36.1 [7.6] kg/m2). There was no difference (P = .27) in Vo2pk assessed by the ITMT and the ISWT (2,266 [478] and 2,017 [561] mL/min, respectively). The Vo2pk measured by the 6MWT (1,778 [360] mL/min) was lower than that measured by the ITMT (P < .01). The limits of agreement for Vo2pk between the ISWT and the ITM were ± 730 mL/min. Cardiorespiratory responses during the ISWT and the ITMT reflected a graded response to a peak, whereas the 6MWT demonstrated a rapid rise to a plateau. CONCLUSIONS The ISWT can be used instead of an ITMT and in preference to the 6MWT to assess cardiorespiratory fitness for a cohort of obese people with treated OSA. However, the imprecision of the agreement in Vo2pk between the ITMT and ISWT means they cannot be used interchangeably in an individual. TRIAL REGISTRY ClinicalTrials.gov; No.: NCT01930513; www.clinicaltrials.gov.

The effects of exercise modality and intensity on energy expenditure and cardiorespiratory response in adults with obesity and treated obstructive sleep apnoea

To inform recommendations for the exercise component of a healthy lifestyle intervention for adults with obesity and treated obstructive sleep apnoea (OSA), we investigated the total energy expenditure (EE) and cardiorespiratory response to weight-supported (cycling) and unsupported (walking) exercise. Individuals with treated OSA and a body mass index (BMI) > 30 kg/m2 performed an incremental cardiopulmonary exercise test on a cycle ergometer and a treadmill to determine the peak oxygen uptake ( V . O 2 pk ) . Participants subsequently completed two endurance tests on each modality, matched at 80% and 60% of the highest V . O 2 pk determined by the incremental tests, to intolerance. The cardiorespiratory response was measured and total EE was estimated from the V . O 2 . Sixteen participants completed all six tests: mean [SD] age 57 [13] years and median [IQ range] BMI 33.3 [30.8–35.3] kg/m2. Total EE during treadmill walking was greater than cycling at both high (158 [101] vs. 29 [15] kcal; p < 0.001) and moderate (178 [100] vs. 85 [59] kcal; p = 0.002) intensities, respectively, with similar cardiorespiratory responses and pattern of EE during rest, exercise and recovery. Contrary to current guidelines, walking might be the preferred training modality to achieve the combination of weight loss and increased cardiorespiratory fitness in adults with obesity and treated OSA.