Higher skeletal muscular metabolic reserve capacity in COPD patients than healthy subjects.

We investigated the interaction between skeletal muscle exercise capacity and central restrictions using exercise modalities, which recruit differing levels of muscle mass in eight patients chronic obstructive lung disease (COPD) (FEV(1)% of predicted; 35 [SE 4%]) and eight healthy controls. Subjects performed conventional bicycling, two-leg knee extensor (2-KE) and single-leg knee extensor (1-KE) exercises. Maximal values for pulmonary VO(2) (VO(2max)), power output, blood lactate, heart rate, blood pressure, and arterial oxygen saturation of hemoglobin were registered. VO(2max) in controls was 2453 (210), 1468 (124), and 976 (76) mL/min during bicycling, 2-KE and 1-KE, respectively. The COPD patients achieved 48% (P<0.05), 62% (P<0.05), and 81% (P=0.10) of the control values. The mass-specific VO(2max) (VO(2max)/exercising muscle mass) during 1-KE was 345 (25) and 263 (30) mL/kg/min (P<0.05) in controls and COPD patients, respectively. During 2-KE the controls and COPD patients achieved 85% (4%) and 67% (5%) (P=0.06) of the mass-specific VO(2) during 1-KE, while during bicycling they achieved 31% (2%) and 17% (1%) (P<0.05), respectively. The COPD patients have central restrictions when exercising with a relatively small muscle mass (2-KE) and have a higher muscular metabolic reserve capacity than controls during whole body exercise.

Four weeks' intensive rehabilitation generates significant health effects in COPD patients.

Changes in health according to World Health Organization's International Classification of Functioning, Disability and Health (ICF) after four weeks of pulmonary rehabilitation (PR) were investigated. Gender differences in the response to PR, and the correlation between improvements in the two components of ICF (Body functions and Activities and Participation) were examined. Twenty-two men and 18 women with chronic obstructive pulmonary disease in Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage II-IV attended in-patient, multidisciplinary PR consisting of endurance training four to five times/week at 70% of peak work rate (WRpeak), resistance training three to four times/week at 72% of 15 repetitions maximum, educational sessions and individual counselling. The results were compared to those of 20 Chronic Obstructive Pulmonary Disease (COPD) patients included after the same criteria and investigated while waiting for admission to PR. In the rehabilitation group, we found significant improvements in health related quality of life (HRQoL) (-7 units, St. George's Respiratory Questionnaire), arm (6%) and leg (15%) maximal voluntary contraction, peak oxygen uptake (6%), WRpeak (60%) and treadmill endurance time (93%). At iso-WR, ventilation and dyspnoea were significantly lower, but inspiratory capacity remained unchanged. Improvements in HRQoL correlated with increases in peak ventilation, but not in muscle strength or exercise capacity. Men improved their six-minute walking distance significantly in contrast to women. Clinically important improvements in HRQoL were found in two out of three of the men, and one out of three of the women. Four weeks of intensive PR generated significant health effects comparable to longer lasting programmes. Changes in exercise capacity and muscle strength were not related to improvements in HRQoL. The gender differences in the response to PR deserve attention in future studies.

The relation between measures of health status and quality of life in COPD.

Because quality of life (QoL) and health status (HS) scales contain different kinds of items and are shown not to be equivalent, there is a recommendation to use both types of scales. We investigated the relationship between either type of scale but focusing on the subscales of HS measures. A sample of chronic obstructive pulmonary disease (COPD) patients completed two QoL scales and two HS scales (BPQ and SGRQ), neuroticism, six-minute walk test and FEV1. Factor analysis revealed a two-factor structure (consistent with previous research), and showed that one type of HS subscale is different from QoL but another is equivalent to QoL. If total HS scores are used then it is valuable to include a QoL measure, but if HS subscales are reported, then these cover both latent variables, with the BPQ providing a clearer separation of the latent variables than the SGRQ.

Gender differences in the performance of activities of daily living among patients with chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) limits the ability to perform activities of daily living (ADL). The Pulmonary Functional Status and Dyspnoea Questionnaire (PFSDQ) measures general dyspnoea, dyspnoea during ADL (dyspnoea score) and loss of functional performance (activity score) for a large number of activities commonly performed by adults. The questionnaire is only validated for male patients. The aim of our study was therefore to validate the PFSDQ for women with COPD. We then wanted to investigate possible gender differences in responses to the PFSDQ and whether associations between the PFSDQ and pulmonary function, exercise capacity, health related quality of life (HRQoL) and general quality of life (QoL) were influenced by gender. This cross-sectional, observational study included 110 COPD patients. Sixty-five men and 45 women, referred to pulmonary rehabilitation participated. Pulmonary function and six-minute walking distance (6MWD) were measured. Patients completed PFSDQ, St George's Respiratory Questionnaire (SGRQ, HRQoL) and Perceived Quality of Life Scale (PQoL, QoL). No gender differences were found in pulmonary function (% of predicted), 6MWD, SGRQ or PQoL. Most items in the PFSDQ were found relevant by both women and men. Activity Scores were only different for men and women for items concerning home management; women had changed their functional performance the most, particularly for the heaviest chores. No gender differences were found in dyspnoea scores. Moderate correlations were found between PFSDQ and 6MWD, SGRQ and PQoL. Multiple linear regression analyses showed that these relations were not influenced by gender. We consider PFSDQ as applicable to women as to men as a comprehensive measure of functional performance and dyspnoea. The questionnaire gives information complementary to measures of exercise capacity, HRQOL and QOL. The larger loss of functional performance in home management among women should be taken into account in the treatment of COPD patients.

Evaluation of the immunocytochemical method for amino acids.

Free amino acids can be coupled to proteins by glutaraldehyde. Rabbits immunised with a bovine serum albumin-glutaraldehyde-amino acid conjugate form antibodies that recognise similar conjugates with brain proteins in glutaraldehyde-fixed tissue. Antisera raised against conjugated GABA (gamma-aminobutyrate), glutamate, aspartate, taurine, glutamine, or glycine were tested against a variety of small molecular compounds that had been fixed by glutaraldehyde to brain protein and immobilised on cellulose ester filters for processing together with the brain sections. This system permitted closely similar conditions for testing and immunocytochemistry. After removing antibodies against the carrier used for immunisation and against cross reacting amino acid conjugates the antisera showed a high specificity. The specific nature of the antisera was corroborated by solid phase adsorption to the homologous antigens and by inhibition experiments with free amino acids and amino acid-glutaraldehyde fixation complexes. After transection of the striatonigral pathway the ipsilateral substantia nigra was almost depleted of GABA-like immunoreactivity; this observation lends additional support to the selectivity of the GABA antiserum. A semiquantitative relation was established between the concentration of amino acid before fixation in a model system and the subsequent intensity of immunostaining. Similar model experiments suggested that the conjugation of an amino acid to brain protein with glutaraldehyde, and the immunoreactivity of the conjugates, may be significantly inhibited in the presence of high concentrations of other amino compounds.