Persistence of impaired health status of Q fever patients 4 years after the first Dutch outbreak.

A significant proportion of Q fever patients from the first Dutch Q fever outbreak in 2007 showed impairment in health status up to 1 year after infection. Interested in whether this decrease in health status persisted, we set out to determine the health status in the same cohort of patients, 4 years after primary infection and to compare health status scores at the individual patient level between 1 and 4 years follow-up. Health status was assessed with the Nijmegen Clinical Screening Instrument (NCSI). Patients were serologically tested to exclude patients with possible, probable or proven chronic Q fever. Results on the NCSI sub-domains at group level [2008 (n = 54) and 2011 (n = 46)] showed a persistent significant percentage of patients exhibiting clinically relevant ('severe') scores for all NCSI sub-domains. After 4 years, undue fatigue was present in 46% and exactly half of all patients experienced a severely impaired general quality of life. Patients with NCSI scores available in both 2008 and 2011 (n = 37) showed no difference in all sub-domain scores, except for a small decrease in dyspnoea emotions in 2011. In this group, a significant proportion of patients either improved or worsened in one or more sub-domains of health status. We conclude that at the group level, health status of Q fever patients remained impaired 4 years after primary infection. At the individual patient level, health status may change.

The economic burden of asthma and chronic obstructive pulmonary disease and the impact of poor inhalation technique with commonly prescribed dry powder inhalers in three European countries.

BACKGROUND: Asthma and chronic obstructive pulmonary disease (COPD) are common chronic inflammatory respiratory diseases, which impose a substantial burden on healthcare systems and society. Fixed-dose combinations (FDCs) of inhaled corticosteroids (ICS) and long-acting ß2 agonists (LABA), often administered using dry powder inhalers (DPIs), are frequently prescribed to control persistent asthma and COPD. Use of DPIs has been associated with poor inhalation technique, which can lead to increased healthcare resource use and costs. METHODS: A model was developed to estimate the healthcare resource use and costs associated with asthma and COPD management in people using commonly prescribed DPIs (budesonide + formoterol Turbuhaler(®) or fluticasone + salmeterol Accuhaler(®)) over 1 year in Spain, Sweden and the United Kingdom (UK). The model considered direct costs (inhaler acquisition costs and scheduled and unscheduled healthcare costs), indirect costs (productive days lost), and estimated the contribution of poor inhalation technique to the burden of illness. RESULTS: The direct cost burden of managing asthma and COPD for people using budesonide + formoterol Turbuhaler(®) or fluticasone + salmeterol Accuhaler(®) in 2015 was estimated at €813 million, €560 million, and €774 million for Spain, Sweden and the UK, respectively. Poor inhalation technique comprised 2.2-7.7 % of direct costs, totalling €105 million across the three countries. When lost productivity costs were included, total expenditure increased to €1.4 billion, €1.7 billion and €3.3 billion in Spain, Sweden and the UK, respectively, with €782 million attributable to poor inhalation technique across the three countries. Sensitivity analyses showed that the model results were most sensitive to changes in the proportion of patients prescribed ICS and LABA FDCs, and least sensitive to differences in the number of antimicrobials and oral corticosteroids prescribed. CONCLUSIONS: The cost of managing asthma and COPD using commonly prescribed DPIs is considerable. A substantial, and avoidable, contributor to this burden is poor inhalation technique. Measures that can improve inhalation technique with current DPIs, such as easier-to-use inhalers or better patient training, could offer benefits to patients and healthcare providers through improving disease outcomes and lowering costs.

Effects of long-acting bronchodilators and prednisolone on inspiratory lung function parameters in stable COPD.

BACKGROUND: In chronic obstructive pulmonary disease (COPD), there is a poor correlation between forced expiratory volume in 1 s (FEV1) and dyspnea following bronchodilator use. Better correlations have been observed between inspiratory lung function parameters (ILPs) and dyspnea, which drives our interest in ILPs. However, the acute and prolonged effects of long-acting bronchodilators and oral corticosteroids on ILPs have not been well investigated. Therefore, the aim of this study was to investigate the effects of these treatments on the ILPs, FEV1, dyspnea (visual analog scale (VAS)) and clinical COPD questionnaire (CCQ). METHODS: Twenty-eight stable COPD patients had their ILPs and FEV1 measured both before and 2 h after the use of a single dose of 18 mcg bronchodilator tiotropium and 50 mcg salmeterol. Thereafter, the patients were randomized to 2 weeks of treatment with 30 mg oral prednisolone once daily or oral placebo in combination with daily treatment with these two bronchodilators. Four weeks after the cessation of the randomized treatment, the ILPs and FEV1 were again measured. After each intervention, any change in the VAS score was assessed. RESULTS: With both bronchodilators, significant improvements in ILPs were demonstrated (p < 0.005), with the exception of changes in ILPs inspiratory capacity (IC) and forced inspiratory flow at 50% of the vital capacity (FIF50) after tiotropium inhalation. After 2 weeks of treatment with prednisolone, significant differences were found for ILP forced inspiratory volume in 1 s (FIV1) and FEV1 compared with placebo. These differences were no longer present 4 weeks after the cessation of prednisolone. Significant relationships between ILPs and VAS scores were only found after 2 weeks of treatment with prednisolone or placebo. CONCLUSIONS: After a single dose of long-acting bronchodilator salmeterol, significant improvements are observed in all ILPs and in FIV1 and PIF after tiotropium. Two weeks of oral corticosteroid treatment improved the FIV1 and FEV1. The dyspnea VAS score was only significantly correlated with the ILPs after 2 weeks of oral corticosteroid treatment.

Non-invasive ventilation abolishes the IL-6 response to exercise in muscle-wasted COPD patients: a pilot study.

Systemic inflammation in patients with chronic obstructive pulmonary disease (COPD) has been related to the development of comorbidities. The level of systemic inflammatory mediators is aggravated as a response to exercise in these patients. The aim of this study was to investigate whether unloading of the respiratory muscles attenuates the inflammatory response to exercise in COPD patients. In a cross-over design, eight muscle-wasted stable COPD patients performed 40 W constant work-rate cycle exercise with and without non-invasive ventilation support (NIV vs control). Patients exercised until symptom limitation for maximally 20 min. Blood samples were taken at rest and at isotime or immediately after exercise. Duration of control and NIV-supported exercise was similar, both 12.9 ± 2.8 min. Interleukin- 6 (IL-6) plasma levels increased significantly by 25 ± 9% in response to control exercise, but not in response to NIV-supported exercise. Leukocyte concentrations increased similarly after control and NIV-supported exercise by ∼15%. Plasma concentrations of C-reactive protein, carbonylated proteins, and production of reactive oxygen species by blood cells were not affected by both exercise modes. This study demonstrates that NIV abolishes the IL-6 response to exercise in muscle-wasted patients with COPD. These data suggest that the respiratory muscles contribute to exercise-induced IL-6 release in these patients.

Exercise in systemic sclerosis intensifies systemic inflammation and oxidative stress.

OBJECTIVE: Exercise testing can be used (i) to evaluate functional limitations of systemic sclerosis (SSc) and (ii) to study whether the inflammatory and oxidative systems are activated after a physical stimulus. The aim of this study was to determine exercise-induced inflammatory and oxidative responses in SSc compared with healthy subjects. METHODS: Eleven patients with SSc and pulmonary involvement and 10 healthy subjects underwent maximal cardiopulmonary exercise testing (CPET). Physiological responses were followed continuously during cycling. Blood samples were taken at rest, during and after maximal exercise to measure inflammatory and oxidative markers. RESULTS: In nine of the 11 SSc patients, cardiocirculatory limitation and gas exchange impairment limited exercise capacity. Basal inflammatory cells, interleukin (IL)-6, and oxidative stress were increased in SSc compared to healthy subjects and intensified after exercise. Basal and exercise-induced inflammation and oxidative stress were correlated with the modified Rodnan skin score. CONCLUSIONS: Although exercise capacity is impaired in patients with SSc, physical activity intensifies the already increased basal levels of systemic inflammation and oxidative stress. These data support the concept of a role for systemic inflammation and oxidative stress in the ongoing systemic effects of SSc.

Maximal exercise capacity in chronic obstructive pulmonary disease: a limited indicator of the health status.

BACKGROUND: Dyspnoea and diminished functional status are pivotal features of the health status (HS) in chronic obstructive pulmonary disease (COPD). However, it is still not fully understood how pulmonary function tests and cardiopulmonary exercise testing relate to these aspects. This may be due to incomplete assessment and/or deficient definitions of HS. Especially regarding peak oxygen consumption, inconsistent results have been reported. OBJECTIVES: To determine the value of maximal cycle ergometry in relation to a broad spectrum of HS aspects. METHODS: 129 patients with COPD, stage II and III according to the GOLD classification, performed a cardiopulmonary exercise test. Sixteen independent sub-domains of HS were assessed according to the Nijmegen Integral Assessment Framework, covering physiological functioning, complaints, functional impairments and quality of life as main domains. VO(2)(max) and HS sub-domains were correlated by bivariate analysis. RESULTS: Weak correlations of VO(2)(max) with most sub-domains were found, except for exercise capacity; the other 5 sub-domains of physiological functioning did not correlate. Between different types of exercise limitation (5 types were differentiated), no significant differences were noted in the scores of 13/16 HS sub-domains. CONCLUSIONS: VO(2)(max) is indeed correlated with most aspects of HS, except for physiological variables, but associations are weak. No single exercise limitation type is associated with specific HS problems. Thus separate assessment of all HS sub-domains is advocated to ensure adequate planning of therapeutic interventions.

The clinical effectiveness of the COPDnet integrated care model.

RATIONALE: Integrated care models have the potential to improve outcomes for patients with COPD. We therefore designed the COPDnet integrated care model and implemented it in two hospitals and affiliated primary care regions in the Netherlands. The COPDnet model consists of a comprehensive diagnostic trajectory ran in secondary care followed by a non-pharmacological intervention program of both monodisciplinary and multidisciplinary components. OBJECTIVE: To assess the clinical effectiveness of the COPDnet integrated care model on health status change in patients with COPD. METHODS: A total of 402 patients with COPD were offered care according to the COPDnet model. At baseline and between 7- and 9-months later health status was measured with the Clinical COPD Questionnaire (CCQ). Primary analysis was carried out for the sample at large. In addition, subgroup analyses were performed after stratification for the type of non-pharmacological intervention where patients had been referred to. RESULTS: The CCQ total score improved statistically significantly from 1.94 ± 1.04 to 1.73 ± 0.96 (P < 0.01) in the 154 patients with valid follow-up measurements. Subgroup analyses revealed significant improvements in the patients receiving pulmonary rehabilitation only. No change in health status was found in patients receiving pharmacotherapy only, carried out self-treatment or who participated in mono-disciplinary primary care offered by allied healthcare professionals. CONCLUSIONS: An improved health status was found in patients with COPD who received care according to the COPDnet integrated care model. Subgroups participating in an interdisciplinary pulmonary rehabilitation program predominantly accounted for this effect.

Clinical relevance of non-tuberculous mycobacteria isolated in the Nijmegen-Arnhem region, The Netherlands.

BACKGROUND: The frequency of clinical isolation of non-tuberculous mycobacteria (NTM) in the Netherlands is increasing, but its clinical relevance is often uncertain. OBJECTIVE: To assess the frequency and clinical relevance of isolation of NTM in four associated hospitals in a single region in the Netherlands. METHODS: Medical files of all patients from whom NTM were isolated between January 1999 and January 2005 were reviewed retrospectively. Diagnostic criteria for non-tuberculous mycobacterial disease published by the American Thoracic Society (ATS) were used to determine clinical relevance. RESULTS: 232 patients were found, from whom NTM were isolated from the respiratory tract in 91% of cases. Patients were mostly white men, with an average age of 60 years and pre-existing pulmonary disease. Fifty-three of 212 patients (25%) with pulmonary isolates met the ATS diagnostic criteria for pulmonary NTM disease; this percentage differed by species. Most patients were treated with rifampicin, ethambutol and clarithromycin. Treatment outcome for pulmonary NTM disease was suboptimal but differed by species: overall, improvement was seen in 67% of treated patients, but in only 50% of those with pulmonary M avium disease. Lymphadenitis was the most common extrapulmonary disease type. CONCLUSIONS: Twenty-five per cent of all patients with pulmonary NTM isolates met the ATS criteria. Clinical relevance differs by species. NTM isolation increases over time. Species distribution differs from that of neighbouring countries and the M avium complex isolates have traits different from those reported in the USA. Adherence to diagnostic and treatment guidelines can be improved.

Clinical relevance of Mycobacterium malmoense isolation in The Netherlands.

Uncertainty exists about the clinical relevance of Mycobacterium malmoense isolation, especially in pulmonary samples. We therefore determined clinical relevance, treatment and outcome of M. malmoense isolation in The Netherlands. A retrospective medical file study was conducted for all patients in The Netherlands from whom Mycobacterium malmoense had been isolated between January 2002 and January 2006. Diagnostic criteria for nontuberculous mycobacterial (NTM) disease published by the American Thoracic Society (ATS) were used to determine clinical relevance. Treatment was compared with guidelines published by the British Thoracic Society. In total, 51 patients were found from whom M. malmoense was isolated. Of these, 40 (78%) patients had pulmonary isolates and 32 (80%) of them met the ATS diagnostic criteria. Cavitary disease was most common (n = 28; 88%). Patients with pulmonary disease were mostly males, with an average age of 56 yrs and pre-existing chronic obstructive pulmonary disease. Cervical lymphadenitis was the most common extrapulmonary disease type. Adherence to treatment guidelines was poor. A good clinical response to treatment was observed in 70% and 73% of patients treated for pulmonary and extrapulmonary disease, respectively. In conclusion, M. malmoense is a clinically highly relevant NTM in The Netherlands causing serious pulmonary morbidity. Adherence to treatment guidelines is not satisfactory.

Clinical relevance of Mycobacterium simiae in pulmonary samples.

The aim of the present study was to determine the clinical relevance of Mycobacterium simiae isolation from clinical samples. The medical files of patients in the Netherlands from whom M. simiae was isolated between 1999 and 2006 were reviewed in order to assess frequency and clinical relevance. Clinical relevance was defined as fulfilment of the diagnostic criteria of the American Thoracic Society. From the files, 28 patients were identified, of whom six (21%) met the American Thoracic Society diagnostic criteria. A slight (54%) female predominance was observed, which is uncommon for nontuberculous mycobacteria isolation. Fulfilment of the diagnostic criteria and initiation of treatment were not in agreement; treatment results were poor. Only a minority of clinical M. simiae isolates are clinically relevant and, applying the American Thoracic Society diagnostic criteria, the number of true infections is overestimated. Physicians in the Netherlands do not always use these criteria in daily practice, resulting in both over- and underdiagnosis of M. simiae infection. Further studies are required in order to improve diagnostic criteria and treatment regimens.

Can free DNA be detected in sputum of lung cancer patients?

SUMMARY: Free DNA is present in the serum of cancer patients in a higher concentration than that in non-cancer patients. Free DNA in sputum may originate from malignant or inflammatory diseases. The aim of the study was to examine the presence of free DNA in sputum and the relationship to lung cancer. The contribution of inflammatory cells was established as well. The amount of free and cellular DNA in sputum was determined using real-time beta-globin PCR in 28 lung cancer patients and 68 controls. Free DNA was present in sputum samples of the cancer patients and controls. We found no differences in DNA concentration in sputum of patients with and without lung cancer. For all patients combined the amount of free DNA was related to the amount of inflammation. Further, we found increased hypermethylation of RASSF1A in lung cancer patients compared to controls to show that tumour related DNA is present in sputum. In conclusion, free DNA can be detected in sputum of lung cancer patients. The amount of free DNA is related to the amount of inflammation, but not to the presence of lung cancer.

Second-line drug resistance in multidrug-resistant tuberculosis cases of various origins in the Netherlands.

SETTING: The Netherlands. OBJECTIVE: To investigate the frequency of resistance to second-line drugs among multidrug-resistant tuberculosis (MDR-TB) cases and its correlation with patients' geographic origin. DESIGN: Retrospective laboratory database study of multidrug-resistant Mycobacterium tuberculosis complex strains isolated in the Netherlands between January 1993 and October 2007. RESULTS: We found 153 patients with MDR-TB, of whom 18 (12%) were native Dutch. Complete second-line drug susceptibility testing was performed for 131 MDR-TB patients. Resistance to second-line drugs was noted in primary samples of 28 (21%) MDR-TB patients. Resistance to a single second-line drug was most frequent (24/28 [86%]; 9 to prothionamide [PTH], 6 to para-aminosalicylic acid, 4 to amikacin [AMK], 4 to ciprofloxacin and 1 to cycloserine). Four MDR-TB patients had strains resistant to multiple second-line drugs; two were extensively drug-resistant M. bovis. In MDR-TB patients of European and Central Asian origin, resistance to second-line drugs was most frequent and involved the widest range of drugs. PTH resistance was frequent among African and American MDR-TB patients, while AMK resistance was frequent among South-East Asians. CONCLUSION: Resistance to second-line drugs is infrequent among MDR-TB patients in the Netherlands. Most second-line drug resistance is recorded among immigrants, with substantial differences in second-line drug resistance in MDR-TB patients originating from different geographical areas.

The rising incidence and clinical relevance of Mycobacterium malmoense: a review of the literature.

The incidence of Mycobacterium malmoense infections compared to other non-tuberculous mycobacteria (NTM) has increased since 1980, especially in northern Europe. Based on various epidemiological and clinical reports outside northern Europe, there is a wide distribution of these infections. Infections with M. malmoense cause pulmonary disease comparable with tuberculosis (TB). The main extra-pulmonary disease type is paediatric cervical lymphadenitis. M. malmoense isolates are clinically significant in about 70-80% of patients. Like other NTM infections, M. malmoense is often found in patients with chronic obstructive pulmonary disease (COPD) and may cause serious morbidity and mortality when inadequately treated. The best treatment consists of a 2-year regimen with rifampicin and ethambutol. The literature on infections with M. malmoense is reviewed with respect to epidemiology, clinical presentation, treatment and outcome.

[The practice guideline 'Asthma in adults' (second revision) from the Dutch College of General Practitioners; a response from the perspective of pulmonology]. / De standaard 'astma bij volwassenen' (tweede herziening) van het Nederlands Huisartsen Genootschap; reactie vanuit de pulmonologie.

The second revised guideline 'Asthma in adults' from the Dutch College of General Practitioners describes the current approach to the diagnosis and treatment of patients with asthma. An interesting change to the guideline is the recommended use of combination medications. The guideline includes new insights into the relationship between peripheral airway inflammation and the clinical severity of asthma. Inhaled corticosteroids with smaller particles are thought to be more effective than traditional corticosteroids. The revised guideline contains recommendations for reducing the local side-effects associated with inhaled corticosteroids. For patients with persistent symptoms despite inhaled medication, a new algorithm can help to determine why symptoms persist before adjusting the medication.

[Practice guideline 'Medical treatment of COPD']. / Richtlijn 'Medicamenteuze behandeling van COPD'.

The practice guideline 'Medical treatment of COPD' completes the practice guideline for diagnostics and non-medicinal treatment. Patients with stable chronic obstructive pulmonary disease (COPD) and minor complaints can be treated with short-acting beta-2-adrenoceptor agonists or anticholinergics or a combination of these. In cases of insufficient clinical control of the condition or if patients use their medication for maintenance, a long-acting bronchodilator is the drug of choice. In patients with severe or very severe COPD (stage III-IV of the criteria of the Global Initiative for Obstructive Lung Disease (GOLD) or with cardiac comorbidity, there is a slight preference for the long-acting anticholinergic tiotropium. Inhaled corticosteroids (ICS) reduce the exacerbation frequency in patients with moderate to severe or very severe COPD (GOLD stage II-IV) and recurrent exacerbations. A combination of ICS with long-acting beta-2-adrenoceptor agonists (LABA) is prescribed in patients with GOLD stage III-IV with at least 2 exacerbations in the past year, a deterioration of the quality of life and with symptoms, if treatment with a LABA alone or an ICS alone results in insufficient improvement. Anticholinergics and beta-2-adrenoceptor agonists have a similar effect on bronchodilation in patients with an acute exacerbation of COPD. If improvement is inadequate, patients with an exacerbation should be treated with prednisolone 30 mg for a period of 7 to 14 days. In outpatients and clinical patients with an exacerbation ofCOPD, an antibiotic is added to prednisolone in very poor lung function (forced expiratory volume in 1 second (FEV1) < 30%) or another risk factor of a severe disease course, such as a respiratory rate > or = 30/min, a systolic blood pressure < 90 mmHg, and disorientation in time, place or person.

[Characteristics and treatment of tuberculosis patients in Dekkerswald, 2000-2005]. / Kenmerken en behandeling van tuberculosepatiënten in Dekkerswald, 2000-2005.

OBJECTIVE: To describe the patient population in Dekkerswald, Nijmegen, one of two tuberculosis (TB) centres in The Netherlands. DESIGN: Descriptive, retrospective study. METHOD: Examination of medical records for all TB patients hospitalised between 2000 and 2005, including demographic, social, clinical and follow-up data. RESULTS: Data from 166 patients were analysed. Tertiary referrals accounted for 98% of all hospitalisations. Most patients (68%) were referred for clinical reasons, and 32% were referred for social reasons. Drug resistance was encountered in 23% of patients; 9% had multidrug-resistant TB. Ten percent of patients were seropositive for HIV. Toxicity and side-effects of treatment often led to changes in treatment (40%). Patients had pulmonary TB (59%), extrapulmonary TB (23%) or both (17%). Overall, 141 patients (85%) completed treatment. The TB-related mortality rate was 5%. CONCLUSION: In Dekkerswald, there is a selected patient population that is characterised by drug-resistance, comorbidity, side-effects, extrapulmonary disease and social issues. Due to the low prevalence of TB in The Netherlands, knowledge and experience regarding complex types of TB are limited. Centralisation of patient care is important to preserve and optimise this expertise.

Budesonide + formoterol delivered via Spiromax® for the management of asthma and COPD: The potential impact on unscheduled healthcare costs of improving inhalation technique compared with Turbuhaler®.

BACKGROUND: Fixed-dose combinations of inhaled corticosteroids and long-acting ß2 agonists are commonly used for the treatment of asthma and COPD. However, the most frequently prescribed dry powder inhaler delivering this medicine - Symbicort® (budesonide and formoterol, BF) Turbuhaler® - is associated with poor inhalation technique, which can lead to poor disease control and high disease management costs. A recent study showed that patients make fewer inhaler errors when using the novel DuoResp® (BF) Spiromax® inhaler, compared with BF Turbuhaler®. Therefore switching patients from BF Turbuhaler® to BF Spiromax® could improve inhalation technique, and potentially lead to better disease control and healthcare cost savings. METHODS: A model was developed to estimate the budget impact of reducing poor inhalation technique by switching asthma and COPD patients from BF Turbuhaler® to BF Spiromax® over three years in Germany, Italy, Sweden and the UK. The model estimated changes to the number, and associated cost, of unscheduled healthcare events. The model considered two scenarios: in Scenario 1, all patients were immediately switched from BF Turbuhaler® to BF Spiromax®; in Scenario 2, 4%, 8% and 12% of patients were switched in years 1, 2 and 3 of the model, respectively. RESULTS: In Scenario 1, per patient cost savings amounted to €60.10, €49.67, €94.14 and €38.20 in Germany, Italy, Sweden and the UK, respectively. Total cost savings in each country were €100.86 million, €19.42 million, €36.65 million and €15.44 million over three years, respectively, with an estimated 597,754, 151,480, 228,986 and 122,368 healthcare events avoided. In Scenario 2, cost savings totalled €8.07 million, €1.55 million, €2.93 million and €1.23 million over three years, respectively, with 47,850, 12,118, 18,319, and 9789 healthcare events avoided. Savings per patient were €4.81, €3.97, €7.53 and €3.06. CONCLUSIONS: We demonstrated that reductions in poor inhalation technique by switching patients from BF Turbuhaler® to BF Spiromax® are likely to improve patients' disease control and generate considerable cost savings through healthcare events avoided.

Metabolic capacity of the diaphragm in patients with COPD.

Chronic obstructive pulmonary disease (COPD) is associated with an increased load on the diaphragm. Chronic loading on skeletal muscles results in metabolic changes and fiber-type shifts. Therefore, we investigated whether the load on the human diaphragm imposed by COPD altered oxidative enzyme activity, glycogenolytic enzyme activity and mitochondrial energy generating capacity and efficiency. Biopsies of the diaphragm from COPD patients and control subjects were obtained and activities of L(+)3-hydroxyacylCoA-dehydrogenase (HADH, marker for beta-oxidation capacity) and phosphorylase (marker for glycogenolytic capacity) were measured spectrophotometrically. Mitochondrial energy generating capacity was measured by spectrophotometrical and radiochemical methods. Fiber-type distribution was determined electrophoretically. We found that HADH activity was increased with increasing severity of COPD (P=0.05). No change in glycogenolytic enzyme activity was observed. The activity of the mitochondrial respiratory chain complexes III and IV and oxidation of pyruvate was increased with increasing airflow obstruction. These results suggest that in COPD the diaphragm adapts to a higher workload by increasing the oxidative capacity and mitochondrial function.