Management of COPD according to guidelines. A national survey among Belgian physicians

Current management of COPD by Belgian physicians was compared with the recommendations of the recently published GOLD guidelines. A random sample of 386 general practitioners and 86 pulmonologists filled in a questionnaire based on the GOLD guidelines and examining their attitudes towards COPD management. Several important deviations from the guidelines were noted. Only few GP's performed spirometry themselves and about 55% of the diagnoses were not based on spirometry. Both GP's and pulmonologists used inhaled corticosteroids considerably more often than prescribed by the guidelines, with 49% and 25% respectively, prescribing them to all COPD patients. Chronic systemic steroids were also overused in stable disease, with 55% of the GP's and 52% of the pulmonologists prescribing them in patients with repeated exacerbations. GP's did not use enough systemic corticosteroids and overused antibiotics in the treatment of exacerbations. Pulmonologists did not pay enough attention to pulmonary rehabilitation, as only 44% of them had a structured programme. Pulmonologists did not use non-invasive ventilation frequently enough in the treatment of exacerbations, as only 22% would use it in the correct indication. Both GP's and pulmonologists did not prescribe enough pharmacotherapy for smoking cessation, with 35% and 46%, respectively using it. Some interesting differences between Dutch and French speaking physicians were noted. These specific deviations from the guidelines will be addressed in a second phase implementation project.

Effects of mechanical ventilation on diaphragm function and biology

The pathophysiological mechanisms of weaning from mechanical ventilation are not fully known, but there is accumulating evidence that mechanical ventilation induces inspiratory muscle dysfunction. Recently, several animal models have provided potential mechanisms for mechanical ventilation-induced effects on muscle function. In patients, weaning difficulties are associated with inspiratory muscle weakness and reduced endurance capacity. Animal studies demonstrated that diaphragm force was already decreased after 12 h of controlled mechanical ventilation and this worsened with time spent on the ventilator. Diaphragmatic myofibril damage observed after 3-days controlled mechanical ventilation was inversely correlated with maximal diaphragmatic force. Downregulation of the diaphragm insulin-like growth factor-I and MyoD/myogenin messenger ribonucleic acid occurred after 24 h and diaphragmatic oxidative stress and increased protease activity after 18 h. In keeping with these findings, diaphragm fibre atrophy was shown after 12 h and reduced diaphragm mass was reported after 48 h of controlled mechanical ventilation. These animal studies show that early alterations in diaphragm function develop after short-term mechanical ventilation. These alterations may contribute to the difficulties in weaning from mechanical ventilation seen in patients. Strategies to preserve respiratory muscle mass and function during mechanical ventilation should be developed. These may include: adaptation of medication, training of the diaphragm, stabilisation of the catabolic state and pharmacotherapy.

Impact of COPD in North America and Europe in 2000: subjects' perspective of Confronting COPD International Survey

To date, no international surveys estimating the burden of chronic obstructive pulmonary disease (COPD) in the general population have been published. The Confronting COPD International Survey aimed to quantify morbidity and burden in COPD subjects in 2000. From a total of 201,921 households screened by random-digit dialling in the USA, Canada, France, Italy, Germany, The Netherlands, Spain and the UK, 3,265 subjects with a diagnosis of COPD, chronic bronchitis or emphysema, or with symptoms of chronic bronchitis, were identified. The mean age of the subjects was 63.3 yrs and 44.2% were female. Subjects with COPD in North America and Europe appear to underestimate their morbidity, as shown by the high proportion of subjects with limitations to their basic daily life activities, frequent work loss (45.3% of COPD subjects of <65 yrs reported work loss in the past year) and frequent use of health services (13.8% of subjects required emergency care in the last year), and may be undertreated. There was a significant disparity between subjects' perception of disease severity and the degree of severity indicated by an objective breathlessness scale. Of those with the most severe breathlessness (too breathless to leave the house), 35.8% described their condition as mild or moderate, as did 60.3% of those with the next most severe degree of breathlessness (breathless after walking a few minutes on level ground). This international survey confirmed the great burden to society and high individual morbidity associated with chronic obstructive pulmonary disease in subjects in North America and Europe.

Alterations in gene expression in hamster diaphragm after emphysema and lung volume reduction surgery

The authors have demonstrated previously that emphysema and lung volume reduction surgery (LVRS) resulted in a significant shift of type IIx/b to type IIa fibres in the diaphragm of hamsters with elastase-induced emphysema. To explore the mechanisms leading to this fibre switching, the mRNA expression of the myogenic regulatory factors, the inhibitors of DNA binding proteins (Id-proteins) and insulin-like growth factor-I were examined. Ribonucleic acid was extracted from the diaphragm of control, emphysematous, emphysematous and sham operated and LVRS hamsters and subjected to reverse transcriptase polymerase chain reaction. Compared to control, the ratio MyoD to myogenin declined with emphysema, sham and even more after LVRS, due to a decrease in MyoD mRNA and an increase in myogenin mRNA. Similarly, compared to control, Id-1 protein mRNA levels decreased significantly in sham and even more in LVRS. Id-2 protein mRNA levels decreased in all groups, but reached statistical significance in LVRS only, compared to control.

IN CONCLUSION

1) the reduced MyoD/myogenin ratio may be the mechanism of the shift to a slower fibre type, 2) the decreased MyoD/myogenin ratio in lung volume reduction surgery animals suggests that lung volume reduction surgery enhances rather than decreases the load placed on the diaphragm and 3) the observed down-regulation of the inhibiting factors may facilitate the diaphragm adaptation to overload.

Resistance versus endurance training in patients with COPD and peripheral muscle weakness

The effects of endurance training on exercise capacity and health-related quality of life (HRQL) in chronic obstructive pulmonary disease (COPD) patients have been studied thoroughly, while resistance training has been rarely evaluated. This study investigated the effects of resistance training in comparison with endurance training in patients with moderate to severe COPD and peripheral muscle weakness (isometric knee extension peak torque <75% predicted). Forty-eight patients (age 64+/-8 yrs, forced expiratory volume in one second 38+/-17% pred) were randomly assigned to resistance training (RT, n=24) or endurance training (ET, n=24). The former consisted of dynamic strengthening exercises. The latter consisted of walking, cycling and arm cranking. Respiratory and peripheral muscle force, exercise capacity, and HRQL were re-evaluated in all patients who completed the 12-week rehabilitation (RT n=14, ET n=16). Statistically significant increases in knee extension peak torque (RT 20+/-21%, ET 42+/-21%), maximal knee flexion force (RT 31+/-39%, ET 28+/-37%), elbow flexion force (RT 24+/-19%, ET 33+/-25%), 6-min walking distance (6MWD) (RT 79+/-74 m, ET 95+/-57 m), maximum workload (RT 15+/-16 Watt, ET 14+/-13 Watt) and HRQL (RT 16+/-25 points, ET 16+/-15 points) were observed. No significant differences in changes in HRQL and 6MWD were seen between the two treatments. Resistance training and endurance training have similar effects on peripheral muscle force, exercise capacity and health-related quality of life in chronic obstructive pulmonary disease patients with peripheral muscle weakness.

Formoterol in patients with chronic obstructive pulmonary disease: a randomized, controlled, 3-month trial

The aim of this study was to investigate formoterol, an inhaled long-acting beta2-agonist, in patients with chronic obstructive pulmonary disease (COPD). Six-hundred and ninety-two COPD patients, mean baseline forced expiratory volume in one second (FEV1) 54%, FEV1/forced vital capacity 75% of predicted, reversibility 6.4% pred, were treated with formoterol (4.5, 9 or 18 microg b.i.d.) or placebo via Turbuhaler for 12 weeks. Symptoms were recorded daily. Spirometry and the incremental shuttle walking test (SWT) were performed at clinic visits. Compared with placebo, 18 microg b.i.d. formoterol reduced the mean total symptom score by 13% and increased the percentage of nights without awakenings by 15%. Formoterol (9 and 18 microg b.i.d.) significantly reduced symptom scores for breathlessness (-7% and -9%, respectively) and chest tightness (-11% and -8%, respectively), reduced the need for rescue medication (-25% and -18%, respectively), and increased symptom-free days (71% and 86%, respectively). FEV1 improved significantly after all three doses of formoterol (versus placebo). No differences were found between groups in SWT walking distance. No unexpected adverse events were seen. In conclusion, 9 and 18 microg b.i.d. formoterol reduced symptoms and increased the number of symptom-free days in a dose-dependent manner in chronic obstructive pulmonary disease patients. Formoterol improved lung function at a dose of 4.5 microg b.i.d. and higher.

What is the optimal treatment strategy for chronic obstructive pulmonary disease exacerbations?

The present study aims to determine whether treating chronic obstructive pulmonary disease (COPD) exacerbations with intravenous steroids and aerosol bronchodilators (group I) is superior to oral steroids and multiple dose inhaler (MDI) bronchodilators with a spacer (group II). Group I received 40 mg methylprednisolone x day(-1) intravenously with a decrease to 20 mg after 10 days and a further decrease of 4 mg x 4 days(-1). Aerosol therapy consisted of 10 mg salbutamol and 1 mg ipratropiumbromide x day(-1). Group II received 32 mg methylprednisolone orally for 1 week followed by 24 mg x day(-1) for 4 days and a subsequent decrease of 4 mg x week(-1). Duovent MDI with a spacer was given at a dose of 1.6 mg fenoterol and 640 microg ipratropiumbromide x day(-1). In group I (n=19) forced expiratory volume in one second (FEV1) rose from 0.82+/-0.46 to 0.91+/-0.47 L and average dyspnoea decreased from 6.0+/-1.9 to 4.1+/-2.6 within 10 days. The Chronic Respiratory Disease Index Questionnaire (CRQ) score increased from 78+/-24 to 90+/-24 points after 4 weeks. In group II (n=18) FEV1 increased from 0.70+/-0.27 to 0.90+/-0.29 L, dyspnoea regressed from 6.2+/-2.4 to 2.7+/-2.6 and CRQ from 67+/-17 to 86+/-20. Both groups showed similar results in dropout rate, length of hospital stay and patient satisfaction. In conclusion, the two treatment strategies appear equally effective in treating chronic obstructive pulmonary disease exacerbations, although oral steroids and metered dose inhaler bronchodilators appear associated with a higher risk of hospital re-admission.

Effects of lung volume reduction surgery in hamsters with elastase-induced emphysema

Lung volume reduction surgery (LVRS) has been shown to improve respiratory mechanics in selected patients with severe emphysema. This is thought to be due to an improvement in lung elastic recoil. This study was aimed at gaining further understanding about the effects of LVRS on respiratory mechanics and airway function. Control hamsters instilled with saline (Ctrl; n=8) were compared with emphysematous animals that underwent either a sham operation (Sham; n=7) or an LVRS (LVRS; n=7). As expected, there was a significant increase in the static lung volumes in the Sham as compared to the Ctrl group and a significant decrease of these volumes in LVRS as compared to the Sham group. Surprisingly, emphysema was associated with a significant increase and LVRS with a significant decrease in vital capacity. Despite a tendency toward an increase in lung compliance as compared to Sham, indices of maximal expiratory flows tended to decrease with LVRS. As opposed to humans, there was no change in the distribution of airway diameters in Sham compared to Ctrl. These findings appear to be largely explained by the high compliance of the hamster chest wall. This allows for better matching between the emphysematous lung and the chest-wall sizes than in humans.

Respiratory muscles in COPD: regulation of trophical status

Chronic obstructive pulmonary disease, COPD is a highly prevalent disorder of increasing medical and socio-economical importance. It is characterized by irreversible airflow obstruction. Besides airflow obstruction also other features are present. One of these is respiratory muscle weakness. Inspiratory muscle weakness is caused by hyperinflation and by generalized muscle weakness causing both respiratory and peripheral muscle dysfunction. The expiratory muscles partake in this generalized muscle weakness. Hyperinflation shortens the inspiratory muscles although in chronic hyperinflation sarcomere adaptation occurs. Generalized muscle weakness is caused by deconditioning, malnutrition, electrolyte disturbances, cardiac failure, systemic inflammation and treatment with corticosteroids causing steroid-induced myopathy. The latter disease was studied intensively both in patients and in animal models of disease. The major findings were that microscopically a myopathic pattern was present associated with generalized fiber atrophy. This is in contrast to classical belief that the atrophy would be confined to type IIx fibers. We noted severe down-regulation of the IGF-I mRNA expression, without important changes in the expression of the binding proteins. This may be responsible for the observed muscle atrophy and the myopathy. The latter is likely to be caused by a simultaneous upregulation of the ubiquitin protease pathway attacking structural proteins. Presently, we study the relationship between local and systemic cytokine expression and respiratory and peripheral muscle dysfunction in COPD patients. Respiratory and peripheral muscle dysfunction have significant consequences for COPD patients. Both respiratory and peripheral muscle dysfunction are associated with reduced exercise tolerance and reduced quality of life. Both are independent determinants of survival, in addition to the degree of airflow obstruction as measured by FEV1. Finally, also the utilization of health care resources appeared to be related to respiratory and peripheral muscle weakness. Treatment of respiratory and peripheral muscle weakness in COPD patients is possible. Respiratory and peripheral muscle training have been shown to produce beneficial effects. Nutritional intervention and anabolic steroids are only useful in combination with muscle training. Systemic administration of growth hormone and IGF-I only produces small effects. In animal models, local administration of IGF-I and transfer of the IGF-I gene transfer appear more promising for the future. Lung volume reduction surgery, LVRS, improves the force-generating capacity of the inspiratory muscles, presumably because of the geometrical alterations it causes in these muscles. It does not appear to improve intrinsic inspiratory muscle function.

The Bronchitis Randomized On NAC Cost-Utility Study (BRONCUS): hypothesis and design. BRONCUS-trial Committee

Chronic obstructive pulmonary disease (COPD) is an irreversible disorder characterized by airflow obstruction and a progressive decline in forced expiratory volume in one second (FEV1). At present, no treatment except quitting smoking appears to affect the progression of the disease. Oxidative stress has been implicated in its pathogenesis. The Bronchitis Randomized on NAC Cost-Utility Study (BRONCUS) is a phase III, randomized, double-blind, placebo-controlled, parallel group, multicentre study designed to assess the effectiveness of the antioxidant agent N-acetylcysteine (NAC) in altering the decline in FEV1, exacerbation rate, and quality of life in patients with moderate to severe COPD. In addition, cost-utility of the treatment will be estimated. Patients will be followed for 3 yrs and evaluated every 3 months. The necessary sample size to demonstrate an effect on the decline in FEV1 of 20 mL x yr(-1) was estimated to be 478 patients. Five hundred and twenty-three patients with moderate to severe COPD were recruited from 10 European countries from June 1, 1997-December 31, 1999. They were 63+/-8 yrs old and consisted of 243 (46%) current smokers and 280 (54%) exsmokers. Patients had on the average 4.9+/-1.6 exacerbations during the last 2 yrs. Postbronchodilator FEVI averaged 57+/-9% and the reversibility after 400 microg of Salbutamol averaged 4+/-4% predicted. The final results of the trial will be available in about 2 yrs. The study will provide objective data on the effects of N-acetylcysteine on outcome variables in chronic obstructive pulmonary disease.

Reduced epithelial expression of secretory component in small airways correlates with airflow obstruction in chronic obstructive pulmonary disease

The epithelial polymeric immunoglobulin receptor/transmembrane secretory component (pIgR/SC) transports into secretions polymeric immunoglobulin A (pIgA), which is considered the first line of defense of the respiratory tract. The present study, done with quantitative immunohistochemistry, evaluated epithelial expression of secretory component (SC) and Clara cell protein (CC16) and neutrophil infiltration into the airways of eight patients with severe chronic obstructive pulmonary disease (COPD) who were undergoing lung transplantation, as compared with these processes in six nonsmoking patients with pulmonary hypertension who were used as controls and in lung specimens from five smokers without chronic bronchitis. Staining for SC was significantly decreased in the COPD patients as compared with the controls, both in large (mean optical density [MOD]: 23.4 [range: 21.1 to 27.8] versus 42.2 [range: 28.2 to 49.3], p = 0.003) and in small airways (MOD: 30.8 [range: 20.3 to 39.4] versus 41.5 [range: 39.2 to 46.2], p = 0.003). SC expression in small airways correlated strongly with functional parameters such as FEV1 (Kendall's tau (K) = 0.76, p = 0.008), FVC (K = 0.64, p = 0.03), and midexpiratory flow at 50% of VC (MEF50) (K = 0.74, p = 0.01). The reduced expression of SC in large airways correlated with neutrophil infiltration in submucosal glands (K = -0.47, p = 0.03). Expression of CC16 in the bronchial epithelium of COPD patients was also significantly decreased as compared with that of controls, especially in small airways (MOD: 28.3 [range: 26.8 to 32.4] versus 45.8 [range: 40.7 to 56.0], p = 0.002), but no correlation was observed with lung function tests. In conclusion, this study shows that reduced expression of SC in airway epithelium is associated with airflow obstruction and neutrophil infiltration in severe COPD.

Exercise training in COPD: how to distinguish responders from nonresponders

PURPOSE

Pulmonary rehabilitation programs consistently have improved exercise capacity, quality of life, and symptoms over the past decade. Although training has been shown to be an essential component of the rehabilitation program, individual patients do not always benefit to the same extent. The present study was designed to investigate which patients were achieving significant benefit of exercise training.

METHODS

Forty-nine stable outpatients with moderate to severe COPD (FEV1 37 (15)%pred) were evaluated before and after 12 weeks of exercise training (3 times per week). Responders in exercise capacity were defined as having 15% increase in maximal workload and/or 25% increase in walking distance, while responders in quality of life showed an improvement of at least 10 points on the chronic respiratory disease questionnaire. With multivariate discriminant analysis, responders were distinguished from nonresponders based upon their initial characteristics.

RESULTS

Thirty-two patients were responders in terms of improved exercise capacity. Ventilatory reserve (VE/MVV), inspiratory muscle strength (Plmax), and peripheral muscle strength (handgrip force and quadriceps force) were significant predictors of the training response (P < 0.05) (accuracy 80% P < 0.001). Although the explained variance was modest, patients that were clearly ventilatory limited and had normal skeletal muscle strength were not likely to benefit from exercise training in terms of exercise capacity. No physiologic variables predicted whether a patient would increase quality of life after exercise training.

CONCLUSION

Patients with reduced exercise capacity who experience less ventilatory limitation to exercise and more reduced respiratory and peripheral muscle strength are more likely to improve with exercise training. Improvements in quality of life after exercise training were significant but remained unpredictable with variables included in the present trial.

Respiratory muscle function and drive in chronic obstructive pulmonary disease

Respiratory, and particularly inspiratory, muscle function is altered in COPD. Many of these alterations are secondary to a mechanical disadvantage related to hyperinflation. Other factors, including corticosteroid therapy and nutritional depletion, are also deleterious to muscle function. In addition, the load imposed on the respiratory muscles is increased in COPD. Combined with the altered respiratory muscle function, this increase induces important changes in respiratory muscle drive and recruitment. Moreover, the imbalance between respiratory muscle function and load is an important determinant of dyspnea and hypercapnia. Because much of the lung and airway derangements are irreversible in COPD, the respiratory muscles appear to be an attractive target for therapeutic interventions.

Distribution of muscle weakness in patients with stable chronic obstructive pulmonary disease

PURPOSE

The authors determined the degree of respiratory and peripheral muscle weakness in patients with moderate to severe chronic obstructive pulmonary disease (COPD). Differences in severity of muscle weakness among muscle groups may provide treatment options, such as selective muscle training, to adapt the exercise prescription in pulmonary rehabilitation programs. In addition, this information may add to the knowledge on the mechanisms of muscle weakness.

METHODS

Respiratory and peripheral muscle force were quantified in 22 healthy elderly subjects and 40 consecutive COPD patients (forced expiratory volume in 1 second, percent of predicted value [% pred] 41 +/- 19; transfer factor for carbon monoxide, % pred 47 +/- 26) admitted to a pulmonary rehabilitation program. Lung function, diffusing capacity, isometric force of four peripheral muscle groups (handgrip, elbow flexion, shoulder abduction, and knee extension), neck flexion force, and maximal inspiratory and expiratory pressures were measured.

RESULTS

Patients had reduced respiratory muscle strength (mean 64% of control subjects' value [% control]) and peripheral muscle strength (mean 75% control) compared to normal subjects. Inspiratory muscle strength (59 +/- 18% control) was significantly lower than expiratory muscle strength (69 +/- 25% control) and peripheral muscle strength (P < 0.01). Neck flexion force (80 +/- 19% control) was better preserved than maximal inspiratory pressure and shoulder abduction force (70 +/- 15% control, P < 0.01). Handgrip force (78 +/- 16% control) and elbow flexion force (78 +/- 14% control) were significantly less affected than shoulder abduction force (70 +/- 15% control, P < 0.01). Finally, shoulder abduction force and knee-extension force (72 +/- 24% control) were not significantly different.

CONCLUSIONS

Muscle weakness in stable COPD patients does not affect all muscles to a similar extent. Inspiratory muscle force is affected more than peripheral muscle force, whereas proximal upper limb muscle strength was impaired more than distal upper limb muscle strength.

Lung volume reduction surgery does not improve diaphragmatic contractile properties or atrophy in hamsters with elastase-induced emphysema

It is claimed that lung volume reduction surgery (LVRS) improves inspiratory muscle function. As diaphragm structure and function are not directly appraisable in patients, we studied the effects of LVRS on the diaphragm in vitro contractile properties and morphology in hamsters with elastase-induced emphysema. Four months after intratracheal instillation of elastase (40 U/100 g), hamsters underwent either bilateral LVRS (LVRS, n = 11) or a sham operation (SHAM, n = 8). Four animals died during the perioperative period in LVRS (n = 7). Hamsters instilled with saline served as control (CTL, n = 8). Animals were studied at the age of 9 mo. LVRS was associated with a significant 25% decrease in functional residual capacity compared to SHAM (p < 0.05). Compared with CTL, LVRS and SHAM showed a significant 18% and 14% reduction in diaphragm mass, respectively (p = 0.02). LVRS had a significantly decreased twitch tension compared to CTL and SHAM (p < 0.01). Both LVRS and SHAM showed increased resistance to muscle fatigue compared with CTL. The histochemical analysis revealed a significant shift from type IIx/b toward type IIa fibers in LVRS and SHAM compared with CTL. In conclusion, emphysema is associated with functional adaptations but LVRS does not appear to beneficially alter the diaphragm contractile and morphological characteristics in hamsters with elastase-induced emphysema.

Short- and long-term effects of outpatient rehabilitation in patients with chronic obstructive pulmonary disease: a randomized trial

PURPOSE

Pulmonary rehabilitation programs are effective in patients with severe chronic obstructive pulmonary disease (COPD) in the short term, but their long-term effects are not known. We investigated the short- and long-term effects of a 6-month outpatient rehabilitation program in patients with severe COPD.

SUBJECTS AND METHODS

One hundred patients were randomly assigned to receive either an exercise training program that included cycling, walking, and strength training (n = 50) or usual medical care (n = 50). Thirty-four patients in the training group were evaluated after 6 months (end of training), and 26 were evaluated after 18 months of follow-up. In the control group, 28 patients were evaluated at 6 months and 23 after 18 months. We measured pulmonary function, 6-minute walking distance, maximal exercise capacity, peripheral and respiratory muscle strength, and quality of life (on a 20 to 140-point scale), and estimated the cost-effectiveness of the program.

RESULTS

At 6 months, the training group showed improvement in 6-minute walking distance [mean difference (training - control) of 52 m; 95% confidence interval (CI), 15 to 89 m], maximal work load (12 W; 95% CI, 6 to 19 W), maximal oxygen uptake (0.26 liters/min; 95% CI, 0.07 to 0.45 liters/min), quadriceps force (18 Nm; 95% CI, 7 to 29 Nm), inspiratory muscle force (11 cm H(2)O; 95% CI, 3 to 20 cm H(2)O), and quality of life (14 points; 95% CI, 6 to 21 points; all P <0.05). At 18 months all these differences persisted (P <0.05), except for inspiratory muscle strength. For 6-minute walking distance and quality of life, the differences between the training group and controls at 18 months exceeded the minimal clinically-important difference.

CONCLUSION

Among patients who completed the 6-month program, outpatient training resulted in significant and clinically relevant changes in 6-minute walking distance, maximal exercise performance, peripheral and respiratory muscle strength, and quality of life. Most of these effects persisted 18 months after starting the program.

Different effects of corticosteroid-induced muscle wasting compared with undernutrition on rat diaphragm energy metabolism

An important adverse effect of corticosteroid treatment is respiratory muscle weakness with diaphragm muscle wasting, but little is known about the underlying pathophysiological processes involved. In order to differentiate between the effects of nutrition depletion and corticosteroids on diaphragm muscle metabolism, a study was performed to investigate the effects of triamcinolone (TR) for 2 weeks and of chronic undernutrition in a pair-weight (PW) group on the structure and energy metabolism of the diaphragm in male Wistar rats compared with a free-fed (FF) group. Diaphragm mass was reduced in TR and PW rats to a similar degree, but the extent of type-IIx/b atrophy was more pronounced in TR rats than in PW rats. No myopathic features were observed after either treatment. ATP in absolute terms as well as the ATP/ADP ratio, total adenine nucleotides, the phosphocreatine (PCr) level and the ratio between PCr and creatine (PCr/Cr) were decreased in the diaphragm of both TR and PW rats. In contrast to the PW group, the total Cr pool was reduced and pyruvate and lactate levels were elevated in the diaphragm of the TR group compared with the FF group. In conclusion, the results of this study indicate that severe undernutrition causes a decrease in muscle energy status resulting in a new metabolic equilibrium, while chronic low-dose TR treatment (0.25 mg/kg per day i.m.) causes a decrease in muscle energy status together with a mismatch between glycolysis and oxidative metabolism.