Baseline dependent minimally important differences for clinical outcomes of pulmonary rehabilitation in people with COPD.

INTRODUCTION: Minimally important differences (MIDs) for common outcomes of pulmonary rehabilitation are well documented for people with chronic obstructive pulmonary disease (COPD). It is not known whether MIDs differ based on COPD disease characteristics. This study aimed to estimate MIDs for clinical outcomes of pulmonary rehabilitation dependent upon baseline characteristics. METHODS: A database containing 2791 people with COPD was split into derivation (n=2245; age 66±9 years; 50% males; FEV1 47±20% predicted) and comparator (n=546; age 66±9 years; 47% males; FEV1 46±21% predicted) cohorts. MIDs were estimated using 0.5 x SD (symmetrically distributed) or 0.5 x IQR (non-symmetrically distributed) for: 6-minute walk test (6MWT), constant work rate test (CWRT), COPD assessment test (CAT), St. George's respiratory questionnaire (SGRQ), hospital anxiety and depression scale (HADS), and fat-free mass index (FFMI). MIDs were estimated based on baseline outcome scores, lung function, modified medical research council (mMRC) grade and FFMI. RESULTS: MID estimates were comparable to previously reported values. MIDs for SGRQ domains (Symptom=8.7 points, Activity=7.1 points, Impact=8.1 points) and FFMI were produced (0.36kg/m2). There was greater variation of change in 6MWT, SGRQ-activity, SGRQ-impact, HADS and FFMI on which the MIDs were determined when categorising for baseline values (all, p<0.05). Greater variation of change in 6MWT on which the MIDs were determined was evident with COPD disease severity grouping (p<0.05). The magnitude of change in 6MWT, CAT, CWRT, SGRQ-activity, and FFMI with baseline mMRC score categorisation resulted in greater variation on which the MIDs were determined (all, p<0.05). Baseline stratification for FFMI resulted in greater variation of change in CWRT (p<0.001) and HADS-depression (p = 0.043) on which MIDs were determined. DISCUSSION: Findings suggest that baseline presentation should be considered for people with COPD when assessing the efficacy of pulmonary rehabilitation. However, clinical significance of the variation underpinning MIDs is yet to be determined.

Reference values for six-minute walk distance and six-minute walk work in Caucasian adults.

RATIONALE: The six-minute walk test (6MWT) is a practical and simple field-based test to assess physical capacity. Several reference equations for six-minute walking distance (6MWD, m) exist, but have a number of limitations that decrease their clinical utility. In addition, no reference equations exist for the 6MWT-derived outcome six-minute walk work (6MWORK, kg.m). OBJECTIVES: To establish new reference equations for 6MWD and 6MWORK on a 20 m course using data from the population-based Canadian Cohort Obstructive Lung Disease study. METHODS AND MEASUREMENTS: A total of 335 participants without obstructive or restrictive pulmonary function, with normal self-reported health status, normal exercise capacity, and <30 pack years cigarette smoking history were selected to create a representative sample of Canadian adults aged ≥40 years. All participants performed two 6MWTs. Reference equations were derived using multiple regression analyses. MAIN RESULTS: On average, 6MWD and 6MWORK were 541±98 m and 41.3 ± 11.2 kg.m, respectively. All outcomes were significantly greater in males than females. Sex-specific reference equations were derived from the results of 6MWD and 6MWORK with an explained variance of 24 to 35%. CONCLUSIONS: This study established reference equations for 6MWD and 6MWORK on a 20 m course in Caucasian males and females aged ≥40 years with normal pulmonary function, self-reported health status and exercise capacity. These newly derived reference equations add value to the assessment of functional capacity in clinical practice.

Prescribing and adjusting exercise training in chronic respiratory diseases - Expert-based practical recommendations.

BACKGROUND: International guidelines recommend endurance (ET) and strength training (ST) in patients with chronic respiratory diseases (CRDs), but only provide rough guidance on how to set the initial training load. This may unintentionally lead to practice variation and inadequate training load adjustments. This study aimed to develop practical recommendations on tailoring ET and ST based on practices from international experts from the field of exercise training in CRDs. METHODS: 35 experts were invited to address a 64-item online survey about how they prescribe and adjust exercise training. RESULTS: Cycling (97%) and walking (86%) were the most commonly implemented ET modalities. Continuous endurance training (CET, 83%) and interval endurance training (IET, 86%) were the frequently applied ET types. Criteria to prescribe IET instead of CET were: patients do not tolerate CET due to dyspnoea at the initial training session (79%), intense breathlessness during initial exercise assessment (76%), and/or profound exercise-induced oxygen desaturation (59%). For ST, most experts (68%) recommend 3 sets per exercise; 62% of experts set the intensity at a specific load that patients can tolerate for a range of 8 to 15 repetitions per set. Also, 56% of experts advise patients to approach local muscular exhaustion at the end of a single ST set. CONCLUSIONS: The experts´ practices were summarized to develop practical recommendations in the form of flowcharts on how experts apply and adjust CET, IET, and ST in patients with CRDs. These recommendations may guide health care professionals to optimize exercise training programs in patients with CRDs.

Test-retest reliability, construct validity and determinants of 6-minute walk test performance in adult patients with asthma.

INTRODUCTION AND OBJECTIVES: Current knowledge regarding the measurement properties of the 6-minute walk test (6MWT) in patients with asthma is limited. Therefore, the aim of this study was to assess the test-retest reliability, measurement error and construct validity of the 6MWT and identify determinants of 6-minute walk distance (6MWD) in patients with asthma. PATIENTS AND METHODS: 201 asthma patients referred for pre-pulmonary rehabilitation assessment, were retrospectively analyzed (age 61±12 years, 42% male, FEV1 78±27% predicted). Patients performed two 6MWTs on subsequent days using a 30 m straight walking course. Other measurements included resting dyspnea, maximal exercise capacity, body composition, pulmonary function, pulmonary and quadriceps muscle strength and symptoms of anxiety and depression. Measurement error (absolute reliability) was tested using standard error of measurement (SEM), minimal detectable change at 95% confidence interval (MDC95%) and Bland and Altman 95% limits of agreement, whereas test-retest reliability (relative reliability) and construct validity were assessed using the intra-class correlation coefficient (ICC2,1) and correlations, respectively. RESULTS: The 6MWD showed excellent test-retest reliability (ICC2,1: 0.91). The mean change in 6MWD after the second 6MWT was 18m (95%CI 11-24m), with 73% of the patients walking further in the second test. The SEM and MDC95% for the 6MWT were 35 m and 98 m, respectively. The best 6MWD correlated strongly with peak oxygen uptake during CPET and resting dyspnea (r = 0.61-0.64) and had no-to-moderate correlations with body composition, pulmonary function, respiratory and quadriceps muscle strength and symptoms of anxiety and depression (r = 0.02-0.45). Multiple linear regression was able to identify maximal workload, BMI, rollator use, maximal expiratory pressure, FEV1 and DLCO as independent determinants of the best 6MWD (R2 = 0.58). CONCLUSIONS: The 6MWT was considered to be reliable and valid in patients with asthma, which strengthens its clinical utility. However, the majority of patients demonstrated a considerable learning effect in the second 6MWT, providing a strong rationale for performing two 6MWTs.

Comorbidity clusters in patients with moderate-to-severe OSA.

PURPOSE: Obstructive sleep apnea (OSA) is a prevalent and multifaceted disease. To date, the presence and severity of objectively identified comorbidities and their association with specific OSA phenotypes, CPAP adherence, and survival remain to be elucidated. The aim of this study is to cluster patients with OSA based on 10 clinically important objectively identified comorbidities, and to characterize the comorbidity clusters in terms of clinical and polysomnographic characteristics, CPAP adherence, and survival. STUDY DESIGN AND METHODS: Seven hundred ten consecutive patients starting CPAP for moderate-to-severe OSA were included. Comorbidities were based on generally accepted cutoffs identified in the peer-reviewed literature. Self-organizing maps were used to order patients based on presence and severity of their comorbidities and to generate clusters. RESULTS: The majority of patients were men (80%). They were generally middle-aged (52 years) and obese (BMI: 31.5 kg/m2). Mean apnea-hypopnea index (AHI) was 41 ± 20 per h of sleep. More than 94% of the patients had one or more comorbidities with arterial hypertension, dyslipidemia, and obesity being the most prevalent. Nine comorbidity clusters were identified. The clinical relevance of these comorbidity clusters was highlighted by the difference in symptoms, PSG parameters, and cardiovascular risk. Also, differences in CPAP adherence, improvements in ESS, and long-term survival were present between the clusters. CONCLUSION: Comorbidity prevalence in patients with OSA is high, and different comorbidity clusters, demonstrating differences in cardiovascular risk, CPAP adherence, and survival, can be identified. These results further substantiate the need for a comprehensive assessment of patients with OSA beyond the AHI.

Carnosine, oxidative and carbonyl stress, antioxidants, and muscle fiber characteristics of quadriceps muscle of patients with COPD.

Oxidative/carbonyl stress is elevated in lower-limb muscles of patients with chronic obstructive pulmonary disease (COPD). Carnosine is a skeletal muscle antioxidant particularly present in fast-twitch fibers. The aims of the present study were to compare muscle carnosine, oxidative/carbonyl stress, antioxidants, and fiber characteristics between patients with COPD and healthy controls (HCs) and between patients after stratification for airflow limitation (mild/moderate vs. severe/very severe), as well as to investigate correlates of carnosine in patients with COPD. A vastus lateralis muscle biopsy was obtained from 40 patients with stable COPD and 20 age- and sex-matched HCs. Carnosine, oxidative/carbonyl stress, antioxidants, fiber characteristics, quadriceps strength and endurance (QE), V̇o2peak (incremental cycle test), and physical activity (PA) were determined. Patients with COPD had a similar carnosine concentration [4.16 mmol/kg wet weight (WW; SD = 1.93)] to HCs [4.64 mmol/kg WW (SD = 1.71)] and significantly higher percentage of fast-twitch fibers and lower QE, V̇o2peak, and PA versus HCs. Patients with severe/very severe COPD had a 31% lower carnosine concentration [3.24 mmol/kg WW (SD = 1.79); n = 15] versus patients with mild/moderate COPD [4.71 mmol/kg WW (SD = 1.83); n = 25; P = 0.02] and significantly lower V̇o2peak and PA versus patients with mild/moderate COPD. Carnosine correlated significantly with QE (rs = 0.427), V̇o2peak (rs = 0.334), PA (rs = 0.379), and lung function parameters in patients with COPD. In conclusion, despite having the highest proportion of fast-twitch fibers, patients with severe/very severe COPD displayed a 31% lower muscle carnosine concentration compared with patients with mild/moderate COPD. As no other markers of oxidative/carbonyl stress or antioxidants were affected, the observed carnosine deficiency is thought to be a possible first sign of muscle redox balance abnormalities.NEW & NOTEWORTHY Carnosine, particularly present in fast-twitch fibers, was investigated in the quadriceps of patients with chronic obstructive pulmonary disease (COPD). Carnosine concentration was similar between patients with COPD and healthy controls but was 31% lower in patients with severe/very severe COPD, despite their high proportion of fast-twitch fibers, versus patients with mild/moderate COPD. As no other markers of oxidative/carbonyl stress or antioxidants were affected, the observed carnosine deficiency is thought to be a possible first sign of muscle redox balance abnormalities.

The correlation between quadriceps muscle strength and endurance and exercise performance in patients with COPD.

To determine the association between quadriceps muscle strength (QMS) and endurance (QME) and exercise capacity in patients with COPD after stratification for sex and resting lung function (LF). Data were collected from 3,246 patients with COPD (60% men, 64 ± 9 yr), including measures of exercise capacity [peak aerobic capacity (peakV̇o2), 6-min walk distance (6MWD)] and isokinetic QMS and QME. Patients were stratified for sex, forced expiratory volume in 1 s (>50/≤50% predicted), single breath carbon monoxide diffusing capacity (>50/≤50% predicted), and residual volume (>140/≤140% predicted). After stratification for resting LF, QMS and QME were significantly associated with peakV̇o2 (r range: 0.47-0.61 and 0.49-0.65 for men and 0.53-0.66 and 0.48-0.67 for women, respectively) and 6MWD (r range: 0.29-0.42 and 0.44-0.55 for men and 0.25-0.54 and 0.34-0.55 for women, respectively) (P < 0.001). Regression models demonstrated that QMS and QME were significant determinants of peakV̇o2 (explained variance R2 range: 35.6%-48.8% for men and 36.8%-49.0% for women) and 6MWD (R2 range: 24.3%-43.3% for men and 28.4%-40.3% for women), independent of age and fat-free mass. Quadriceps muscle function was significantly associated with peakV̇o2 and 6MWD in male and female patients with COPD after stratification for resting LF, in which QME appear to be a more important determinant than QMS. This underlines the importance of systematically evaluating both quadriceps muscle strength and endurance in in all patients with COPD.NEW & NOTEWORTHY Our findings identified quadriceps muscle function as an important determinant of exercise capacity across a wide spectrum of lung function. Quadriceps muscle endurance appears to be a more important determinant than quadriceps muscle strength, underlining the importance of including both the measurement of quadriceps muscle strength and endurance in routine assessment for all patient with COPD.

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.

Impact of pulmonary rehabilitation on activities of daily living in patients with chronic obstructive pulmonary disease.

A high proportion of patients with chronic obstructive pulmonary disease (COPD) experience problems during the performance of activities of daily living (ADLs). We aimed to determine the effects of a comprehensive 8-wk pulmonary rehabilitation program on the physiologic response to and performance of ADLs in patients with COPD. Before and after pulmonary rehabilitation, 31 patients with COPD [71% men; mean age: 64.2 (SD 8.4) years; mean forced expiratory volume in the first second: 54.6 (SD 19.9) % predicted] performed physical function tests, the Canadian Occupational Performance Measure (COPM), and an ADL test consisting of the following: putting on socks, shoes, and vest; stair climbing; washing up four dishes, cups, and saucers; doing groceries and putting away groceries in a cupboard; folding eight towels; and vacuum cleaning for 4 min. Metabolic load, ventilation, and dynamic hyperinflation were assessed using an Oxycon mobile device. In addition, symptoms of dyspnea and fatigue and time to complete ADLs were recorded. After rehabilitation, patients with COPD used a significantly lower proportion of their peak aerobic capacity and ventilation to perform ADLs, accompanied by lower Borg scores for dyspnea and fatigue. Furthermore, patients needed significantly less time to complete ADLs. Dynamic hyperinflation occurred during the performance of ADLs, which did not change following pulmonary rehabilitation. Changes in physical function, including six-min walk distance, constant work rate test, quadriceps muscle strength, and COPM were significantly correlated with change in average total oxygen uptake during the performance of the ADL test. A comprehensive pulmonary rehabilitation program can improve the physiologic response to and actual performance of ADLs in patients with COPD. NEW & NOTEWORTHY A high proportion of patients with chronic obstructive pulmonary disease (COPD) experience problems during the performance of activities of daily living (ADLs). This study clearly demonstrated that a comprehensive pulmonary rehabilitation program can improve the performance of ADLs in patients with COPD, indicated by a significantly shorter time to perform ADLs and a lower metabolic load and dyspnea sensation.

How to determine an impaired health status in COPD: Results from a population-based study.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is associated with a significantly impaired health status and lost work productivity across all degrees of airflow limitation. The current study investigated whether an impaired health status is better represented by the recommended COPD Assessment Test (CAT) cut-point of 10 points, or the 95th percentile of the CAT score in a non-COPD population. Additionally, the impact of COPD on health status in a Dutch population, after stratification for work status, was measured. METHODS: Demographics, clinical characteristics, post-bronchodilator spirometry, and CAT were assessed in subjects from the Longitudinal Aging Study Amsterdam (LASA), a large Dutch population-based study. Normative values for the CAT score were described by percentiles using the mean, standard deviation, median and range. RESULTS: In total, 810 COPD and non-COPD subjects (50.4% male, mean age 60.5 ±; 2.9 years) were analysed. Significant differences were observed in CAT scores between non-COPD and COPD subjects (6.7 ±; 5.2 vs. 9.5 ±; 5.9, p < 0.001 respectively). The proportion of COPD subjects with an impaired health status differed between applying the CAT ≥ 10 cut-point (50.0%) and applying the 95th percentile of CAT in non-COPD subjects (> 18 cut-point; 7.6%). Higher CAT scores were seen in working COPD patients compared with working non-COPD subjects (9.3 ±; 5.2 vs. 6.0 ±; 4.6, p < 0.001). CONCLUSION: We suggest a CAT cut-point of > 18 points to indicate an impaired health status in COPD. This would imply an adaptation of the current GOLD classification of the disease.

Relationship between pulmonary rehabilitation and care dependency in COPD.

The aims of this study were to explore care dependency before and after pulmonary rehabilitation (PR) in patients with COPD (n=331) and to compare the response to PR between care dependent and independent patients. At baseline, 85 (25.7%) patients had a Care Dependency Scale (CDS) score ≤68 points and were considered as care dependent. CDS scores of these patients improved after PR (p<0.001). After PR, CDS score of 38 (44.7%) patients with a baseline CDS score ≤68 points increased to >68 points. Patients with a baseline CDS score ≤68 points or >68 points showed after PR a comparable improvement in COPD Assessment Test, Hospital Anxiety and Depression Scale and 6-min walk distance (all p<0.05). TRIAL REGISTRATION NUMBER: NTR3416 (The Netherlands).

Quality of dietary intake in relation to body composition in patients with chronic obstructive pulmonary disease eligible for pulmonary rehabilitation.

BACKGROUND/OBJECTIVES: A poor dietary quality may accelerate disturbances in body composition in chronic obstructive pulmonary disease (COPD), but only limited studies have investigated dietary intake from this perspective. The objective of the current study was to investigate dietary intake in relation to low fat-free mass and abdominal obesity in COPD. SUBJECTS/METHODS: Dietary intake was assessed by means of a cross-check dietary history method in 564 COPD patients referred for pulmonary rehabilitation. The Dutch Food Composition Database was used to calculate nutrient intake, which was compared with the 2006 recommendations from the Dutch Health Council. Body composition was assessed by DEXA scan. RESULTS: In general, the reported intake of macronutrients represented a typical western diet. With regard to micronutrients, vitamin D and calcium intakes were below the recommended levels in the majority of patients (>75%), whereas vitamin A, C and E intakes were below the recommended levels in over one-third of patients. Patients with inadequate vitamin D intake more frequently reported a low intake of protein (P=0.02) and micronutrients (P<0.001). Patients with a low fat-free mass index (FFMI) more often had low intake of protein, while abdominally obese patients more often had low intake of protein and most micronutrients (P<0.05). Patients with both low FFMI and abdominal obesity appeared most often to be consuming a poor-quality diet. CONCLUSIONS: Our data indicate that dietary quality is low in COPD patients referred for pulmonary rehabilitation and differs between patients with different body composition profiles.

Physical inactivity and risk of hospitalisation for chronic obstructive pulmonary disease.

The association between physical activity and risk of hospitalisation for chronic obstructive pulmonary disease (COPD) is not yet clear. We conducted a systematic review of the literature to fill this gap in knowledge. Eight electronic databases were searched using a selection of controlled vocabulary and keywords. The search resulted in more than 1000 initial hits, of which four met the inclusion criteria. For each identified study, relevant data were extracted and appraised. The results indicate that less physically active patients with COPD were more likely to be admitted to hospital. Consistent with a lower level of physical activity, the patients tended to have shorter walking times as well as spend fewer hours outdoors. In multivariate regression analysis, self-reported physical activity predicted hospitalisation in patients from the general population and re-hospitalisation in patients admitted for an acute exacerbation. The evidence for an association between physical activity and risk of hospitalisation for COPD is limited to a few prospective cohort studies. More research is needed to quantify the degree of physical activity associated with reduced risk of hospitalisation.

Patient-clinician communication about end-of-life care for Dutch and US patients with COPD.

Improving patient-clinician communication about end-of-life care is important in order to enhance quality of care for patients with chronic obstructive pulmonary disease (COPD). Our objective was to compare quality of patient-clinician communication about end-of-life care, and endorsement of barriers and facilitators to this communication in the Netherlands and the USA. The present study was an analysis of survey data from 122 Dutch and 391 US outpatients with COPD. We compared quality of patient-clinician communication about end-of-life care (Quality of Communication questionnaire) and barriers and facilitators to communication about end-of-life care (Barriers and Facilitators Questionnaire) between the Netherlands and the USA, controlling for patients' demographic and illness characteristics. Although Dutch patients in this study had worse lung function and disease-specific health status than US patients, Dutch patients reported lower quality of communication about end-of-life care (median score 0.0 (interquartile range 0.0-2.0) versus 1.4 (0.0-3.6); adjusted p<0.005). Clinicians in both countries rarely discussed life-sustaining treatment preferences, prognoses, dying processes or spiritual issues. Quality of communication about end-of-life care needs to improve in the Netherlands and the USA. Future studies to improve this communication should be designed to take into account international differences and patient-specific barriers and facilitators to communication about end-of-life care.

Reproducibility of 6-minute walking test in patients with COPD.

The reproducibility of the 6-min walking test (6MWT) needs to be more solidly studied. This study aimed to investigate the reproducibility of two 6MWTs performed on subsequent days in a large and representative sample of patients with chronic obstructive pulmonary disease (COPD), and to quantify the learning effect between the two tests, as well as its determinants. In a retrospective observational study, 1,514 patients with COPD performed two 6MWTs on subsequent days. Other measurements included body composition (dual X-ray absorptiometry), dyspnoea (Medical Research Council scale) and comorbidity (Charlson index). Although the 6MWT was reproducible (intraclass correlation coefficient = 0.93), patients walked farther in the second test (391 m, 95% CI 155-585 m versus 418 m, 95% CI 185-605 m; p<0.0001). On average, the second 6MWT increased by 27 m (or 7%), and 82% of patients improved in the second test. Determinants of improvement ≥ 42 m in the second test (upper limit of the clinically important change) were as follows: first 6MWT <350 m, Charlson index <2 and body mass index <30 kg · m(-2) (OR 2.49, 0.76 and 0.60, respectively). The 6MWT was statistically reproducible in a representative sample of patients with COPD. However, the vast majority of patients improved significantly in the second test by an average learning effect of 27 m.

The prevalence of quadriceps weakness in COPD and the relationship with disease severity.

Quadriceps strength relates to exercise capacity and prognosis in chronic obstructive pulmonary disease (COPD). We wanted to quantify the prevalence of quadriceps weakness in COPD and hypothesised that it would not be restricted to patients with severe airflow obstruction or dyspnoea. Predicted quadriceps strength was calculated using a regression equation (incorporating age, sex, height and fat-free mass), based on measurements from 212 healthy subjects. The prevalence of weakness (defined as observed values 1.645 standardised residuals below predicted) was related to Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage and Medical Research Council (MRC) dyspnoea score in two cohorts of stable COPD outpatients recruited from the UK (n = 240) and the Netherlands (n = 351). 32% and 33% of UK and Dutch COPD patients had quadriceps weakness. A significant proportion of patients in GOLD stages 1 and 2, or with an MRC dyspnoea score of 1 or 2, had quadriceps weakness (28 and 26%, respectively). These values rose to 38% in GOLD stage 4, and 43% in patients with an MRC Score of 4 or 5. Quadriceps weakness was demonstrable in one-third of COPD patients attending hospital respiratory outpatient services. Quadriceps weakness exists in the absence of severe airflow obstruction or breathlessness.

Current status of research on osteoporosis in COPD: a systematic review.

Patients with chronic obstructive pulmonary disease (COPD) are at increased risk of osteoporosis. However, the prevalence, correlates and effectiveness of treatment of osteoporosis in COPD patients remain unclear. We performed a systematic review of the literature to answer three questions. 1) What is the prevalence of osteoporosis in COPD? 2) What are identified correlates of osteoporosis in COPD? 3) What are the effects of treatment of osteoporosis in COPD? A computerised literature search in MEDLINE/PubMed and the Cochrane database was carried out. In addition, reference lists were searched by hand and authors were contacted if necessary. The prevalence of osteoporosis and osteopenia varied 9-69% and 27-67%, respectively. Prevalence of osteoporosis was generally higher than in healthy subjects and some other chronic lung diseases. Correlates of osteoporosis in COPD are mainly measures of body composition, disease severity and the use of corticosteroids, although causality has not been proven. Effects of treatment of osteoporosis have not been investigated in samples consisting of COPD patients only. Longitudinal follow-up to assess determinants of osteoporosis in COPD and randomised placebo-controlled trials on the effects of treatment of osteoporosis in patients with COPD only are warranted.

Effects of moderate-to-high intensity resistance training in patients with chronic heart failure.

CONTEXT: Resistance training may be beneficial for patients with chronic heart failure (CHF). OBJECTIVE: To systematically review the methodological quality of, and summarise the effects of, moderate-to-high intensity resistance training in CHF. DATA SOURCES: Medline/PubMed, Science Citation Index Expanded, SSCI and A&HCI. STUDY SELECTION: English language (non-)randomised controlled trials. DATA EXTRACTION: A predesigned data extraction form was used to obtain data on trial design and relevant results. Methodological quality of the identified trials were scored using the Delphi list. RESULTS: Most of the 10 trials identified had moderate-to-severe methodological limitations. Effects of resistance training (alone or in combination with endurance training) are inconclusive for outcomes like exercise capacity and disease-specific quality of life. CONCLUSIONS: Even though moderate-to-high intensity resistance training does not seem be harmful for patients with CHF, the current peer-reviewed evidence seems inadequate to generally recommend incorporation of resistance training into exercise-based rehabilitation programmes for patients with CHF.