Muscle Strength and Quality of Life in Patients With COPD
Twenty patients with COPD between the ages of 40–80 who were not taking antibiotics and had not made any changes in their medications for at least three weeks (mean FEV1 49.3 ± 19.2%, 5 female and 15 male) and a group of age-and-sex-matched healthy subjects (4 female and 16 male) were included in this cross-sectional study. The patients who were redirected from the Hacettepe University Hospitals, Department of Chest Diseases, Ankara, Turkey for pulmonary rehabilitation and willing to participate in the study were recruited. The healthy subjects were volunteers without any lung, heart or systemic disease or handicap in physical effort. Patients who have physical disability to perform the tests and could not cooperate for the tests were not included in the study. The assessments were applied in the Hacettepe University, Faculty of Health Sciences, Department of Physiotherapy and Rehabilitation, Cardiopulmonary Rehabilitation Unit, Ankara Turkey. The study was approved by the Ethical Committee of Hacettepe University, patients and healthy subjects who decided to participate in the study signed an informed consent form.
The physical and sociodemographic characteristics of all subjects were recorded. Dyspnea levels of subjects were evaluated using the Modified Medical Research Council (MMRC) Dyspnea Scale. This is a categorical scale ranging from 0 to 4, where patients choose the statement that best describes their dyspnea level from five choices.
The pulmonary function test according to American Thoracic Society/European Respiratory Society (ATS/ETS) criteria was performed with a Spirolab III spirometer (Spirolab, Medical International Research, Rome, Italy) in the sitting position. The pulmonary function test results were expressed as percentages of the expected values adjusted for age, height, body weight and sex.
Peripheral muscle strength (knee extensor, shoulder abductor and flexor, and hand grip strength) was measured using a digital hand-held dynamometer (JTECH, Medical Commander Powertrack II, USA). Peripheral muscle strength testing was repeated three times for each muscle and the mean value in Newtons (N) was recorded. The average values of the left and right sides was then taken for statistical analysis. Peripheral muscle endurance was assessed with a sit-ups test, a modified push-ups test and a squat test. In the sit-ups test, patients were asked to lift up the trunk from the supine position until the lower the angle of the scapula with the arms stretched forward consecutively as quickly as possible. For the modified push-ups test, patients were requested to only lift their trunk performing consecutive elbow flexions and extensions in the push-up position as quickly as possible. The squat test required the patient to move as quickly as possible from a standing position to a squatting position. Each tests were performed for 30 seconds and the numbers of sit-ups, push-ups and squats were recorded for analysis.
For the 6MWT, the patients were requested to walk along a flat corridor as fast as they could in their walking speed for six minutes. The test was administered twice in the same day with a half-hour interval. Pre- and post-test heart rate (HR) and oxygen saturation (SpO2) with a pulse oxymeter (KPTS, Seoul, Korea) were recorded. General and quadriceps fatigue and dyspnea perception were assessed with Modified Borg Scale and pre- and post-test scores were recorded. For each patient, result of the tests with the longest distance was used in the statistical analysis. The 6MWT distance was expressed as percentages of the expected values from age and sex (6MWT% of distance).
After physical assessments, the patients and healthy subjects answered questionnaires about fatigue and quality of life by themselves. The subjects answered questionnaires completed by selecting the most suitable option for them. The fatigue perception of the subjects were evaluated by the Fatigue Impact Scale (FIS) and the Fatigue Severity Scale (FSS). FIS is a multidimensional scale consisting of 40 questions to evaluate the patient's perception of the limitations caused by fatigue during the last month in the physical (10 items), cognitive (10 items) and psychosocial (20 items) functions. Each question is answered by a choice ranging from a score of 0 (no problem) to 4 (extreme problems). Total score ranges between 0 and 160. High scores indicate a higher effect of fatigue. FSS is one of the most frequently used 9-item one-dimensional scale developed for evaluating fatigue. Patients are asked to provide a score for each item on a range from 1 (strongly disagreement) to 7 (strongly agreement), a score of ≥4 indicates severe fatigue. FSS is reliable and valid assesment tool for the Turkish population.
The Nottingham Health Profile (NHP) is a reliable general quality of life questionnaire developed to provide a summary index on the patient's perception of emotional, social and physical health problems and adaptation of the NHP was made for the Turkish people (24). In this study, only the first part of this questionnaire was used to evaluate the subjects' general quality of life. This first part contains 38 items evaluating the perception of limitation or discomfort, divided over six sub-dimensions: energy level (3 items), pain (8 items), emotional reaction (9 items), sleep (5 items), social isolation (5 items), and physical abilities (8 items). The total score for each section is 0–100. High scores indicate worse quality of life.
The Leicester Cough Questionnaire (LCQ) is a valid and reliable health status measure for adults with chronic cough and patients with COPD that indicates the effect of cough on quality of life and the efficacy of cough-modifying agents during the last two weeks. Adaptation of the LCQ was made for the Turkish people (25). It contains a total of 19 items that are divided into the physical (8 items), psychosocial (7 items) and social (4 items) sub-dimensions. The answer to each items is scored 1–7. Total score varies from 3 to 21. Low scores on the LCQ indicate a higher effect of coughing on the subject.
The statistical evaluation was performed using the SPSS 15.0 statistical packet software for Windows. Variables were descriptively expressed as mean ± standard deviation, frequency and percentage. Normal distribution was evaluated by the Shapiro-Wilk test and histograms and the assumptions of the parametric tests were met by the data. The continuous variables were compared using the two-tailed Student's t-test and variables determined by counting were compared with the two-tailed Chi-squared test. Correlations between dyspnea and fatigue perception, peripheral muscle strength, general and cough-specific quality of life in patients with COPD were evaluated using the two-tailed Spearman's correlation analysis as the conditions required for parametric tests were not fulfilled. Correlations were characterized as "high" (r > 0.70), "moderate" (r = 0.50–0.69), "low" (r = 0.26–0.49) and "little or no correlation" (r = 0.00–0.25). Significance was set at α < 0.05.
Methods
Twenty patients with COPD between the ages of 40–80 who were not taking antibiotics and had not made any changes in their medications for at least three weeks (mean FEV1 49.3 ± 19.2%, 5 female and 15 male) and a group of age-and-sex-matched healthy subjects (4 female and 16 male) were included in this cross-sectional study. The patients who were redirected from the Hacettepe University Hospitals, Department of Chest Diseases, Ankara, Turkey for pulmonary rehabilitation and willing to participate in the study were recruited. The healthy subjects were volunteers without any lung, heart or systemic disease or handicap in physical effort. Patients who have physical disability to perform the tests and could not cooperate for the tests were not included in the study. The assessments were applied in the Hacettepe University, Faculty of Health Sciences, Department of Physiotherapy and Rehabilitation, Cardiopulmonary Rehabilitation Unit, Ankara Turkey. The study was approved by the Ethical Committee of Hacettepe University, patients and healthy subjects who decided to participate in the study signed an informed consent form.
The physical and sociodemographic characteristics of all subjects were recorded. Dyspnea levels of subjects were evaluated using the Modified Medical Research Council (MMRC) Dyspnea Scale. This is a categorical scale ranging from 0 to 4, where patients choose the statement that best describes their dyspnea level from five choices.
The pulmonary function test according to American Thoracic Society/European Respiratory Society (ATS/ETS) criteria was performed with a Spirolab III spirometer (Spirolab, Medical International Research, Rome, Italy) in the sitting position. The pulmonary function test results were expressed as percentages of the expected values adjusted for age, height, body weight and sex.
Peripheral muscle strength (knee extensor, shoulder abductor and flexor, and hand grip strength) was measured using a digital hand-held dynamometer (JTECH, Medical Commander Powertrack II, USA). Peripheral muscle strength testing was repeated three times for each muscle and the mean value in Newtons (N) was recorded. The average values of the left and right sides was then taken for statistical analysis. Peripheral muscle endurance was assessed with a sit-ups test, a modified push-ups test and a squat test. In the sit-ups test, patients were asked to lift up the trunk from the supine position until the lower the angle of the scapula with the arms stretched forward consecutively as quickly as possible. For the modified push-ups test, patients were requested to only lift their trunk performing consecutive elbow flexions and extensions in the push-up position as quickly as possible. The squat test required the patient to move as quickly as possible from a standing position to a squatting position. Each tests were performed for 30 seconds and the numbers of sit-ups, push-ups and squats were recorded for analysis.
For the 6MWT, the patients were requested to walk along a flat corridor as fast as they could in their walking speed for six minutes. The test was administered twice in the same day with a half-hour interval. Pre- and post-test heart rate (HR) and oxygen saturation (SpO2) with a pulse oxymeter (KPTS, Seoul, Korea) were recorded. General and quadriceps fatigue and dyspnea perception were assessed with Modified Borg Scale and pre- and post-test scores were recorded. For each patient, result of the tests with the longest distance was used in the statistical analysis. The 6MWT distance was expressed as percentages of the expected values from age and sex (6MWT% of distance).
After physical assessments, the patients and healthy subjects answered questionnaires about fatigue and quality of life by themselves. The subjects answered questionnaires completed by selecting the most suitable option for them. The fatigue perception of the subjects were evaluated by the Fatigue Impact Scale (FIS) and the Fatigue Severity Scale (FSS). FIS is a multidimensional scale consisting of 40 questions to evaluate the patient's perception of the limitations caused by fatigue during the last month in the physical (10 items), cognitive (10 items) and psychosocial (20 items) functions. Each question is answered by a choice ranging from a score of 0 (no problem) to 4 (extreme problems). Total score ranges between 0 and 160. High scores indicate a higher effect of fatigue. FSS is one of the most frequently used 9-item one-dimensional scale developed for evaluating fatigue. Patients are asked to provide a score for each item on a range from 1 (strongly disagreement) to 7 (strongly agreement), a score of ≥4 indicates severe fatigue. FSS is reliable and valid assesment tool for the Turkish population.
The Nottingham Health Profile (NHP) is a reliable general quality of life questionnaire developed to provide a summary index on the patient's perception of emotional, social and physical health problems and adaptation of the NHP was made for the Turkish people (24). In this study, only the first part of this questionnaire was used to evaluate the subjects' general quality of life. This first part contains 38 items evaluating the perception of limitation or discomfort, divided over six sub-dimensions: energy level (3 items), pain (8 items), emotional reaction (9 items), sleep (5 items), social isolation (5 items), and physical abilities (8 items). The total score for each section is 0–100. High scores indicate worse quality of life.
The Leicester Cough Questionnaire (LCQ) is a valid and reliable health status measure for adults with chronic cough and patients with COPD that indicates the effect of cough on quality of life and the efficacy of cough-modifying agents during the last two weeks. Adaptation of the LCQ was made for the Turkish people (25). It contains a total of 19 items that are divided into the physical (8 items), psychosocial (7 items) and social (4 items) sub-dimensions. The answer to each items is scored 1–7. Total score varies from 3 to 21. Low scores on the LCQ indicate a higher effect of coughing on the subject.
The statistical evaluation was performed using the SPSS 15.0 statistical packet software for Windows. Variables were descriptively expressed as mean ± standard deviation, frequency and percentage. Normal distribution was evaluated by the Shapiro-Wilk test and histograms and the assumptions of the parametric tests were met by the data. The continuous variables were compared using the two-tailed Student's t-test and variables determined by counting were compared with the two-tailed Chi-squared test. Correlations between dyspnea and fatigue perception, peripheral muscle strength, general and cough-specific quality of life in patients with COPD were evaluated using the two-tailed Spearman's correlation analysis as the conditions required for parametric tests were not fulfilled. Correlations were characterized as "high" (r > 0.70), "moderate" (r = 0.50–0.69), "low" (r = 0.26–0.49) and "little or no correlation" (r = 0.00–0.25). Significance was set at α < 0.05.
Source...