Acute effects of hyperoxia on resting pattern of ventilation and dyspnoea in COPD

Background and objective:   Hyperoxia has been shown to reduce resting ventilation, hyperinflation and dyspnoea in patients with severely hypoxaemic COPD. This study assessed the effects of hyperoxia on these resting measures in patients with COPD of varying disease severity and characterized those patients who responded.
Methods:   Measurements of dyspnoea (Borg score), oxyhaemoglobin saturation (SpO₂), inspiratory capacity (IC), minute ventilation, tidal volume, breathing and cardiac frequency were performed at rest in 51 patients with COPD while they breathed air and 44% oxygen, in a randomized double-blinded fashion.
Results:   Hyperoxia induced significant reductions in cardiac frequency and dyspnoea and a significant increase in SpO₂. No significant change was noted in IC for the group overall, and there was substantial inter-subject variation in this measurement. No significant changes were found in ventilation, and there was no correlation between change in dyspnoea and change in IC. In patients with moderate to severe airflow obstruction (FEV₁ < 70% predicted), a significant association was found between the degree of airflow obstruction and change in IC induced by hyperoxia.
Conclusions:   Hyperoxia improved dyspnoea but did not significantly alter resting pulmonary hyperinflation in a group of patients with COPD of varying severity. However, in a subset patients with moderate to severe airflow obstruction a relationship existed between the severity of airflow obstruction and volume response to hyperoxia.     

Non-invasive ventilation during arm exercise and ground walking in patients with chronic hypercapnic respiratory failure

Background and objective:   People with chronic hypercapnic respiratory failure (HRF) often have a ventilatory limitation to exercise with difficulty performing activities of daily living. Although non-invasive ventilation (NIV) appears to reduce the ventilatory limitation and improve exercise performance in people with severe COPD, the effect of NIV during functional activities such as unsupported arm exercise (UAE) and ground walking in people with chronic HRF is unclear.
Methods:   Seventeen patients with chronic HRF (PaCO₂ 52.1 ± 5.3 mm Hg) performed a series of UAE tests, and 15 patients (PaCO₂ 51.7 ± 3.8 mm Hg) performed a series of endurance shuttle walk tests, with and without NIV in a randomized cross-over design.
Results:   NIV during UAE increased endurance time by a mean of 91 s (95% confidence interval (CI): 10–172, P  = 0.031) and reduced dyspnoea by a mean of 2.3 on the Borg scale (95% CI: 1.0–3.7, P  = 0.002) compared with exercise without NIV. There was a non-significant increase in walking endurance time with NIV during exercise (119 s, 95% CI: −17 to 254, P  = 0.081); however, isotime dyspnoea was unchanged compared with walking without NIV (−1.0, 95% CI: −3.0 to 1.0, P  = 0.29).
Conclusion:   NIV during UAE increased endurance time and reduced dyspnoea compared with exercise without NIV in patients with chronic HRF. Investigation of the role of NIV as an adjunct to UAE training is warranted. In contrast, NIV during ground walking did not improve exercise capacity. However, the pressure support provided may have been inadequate as dyspnoea was not reduced.     

Association between angiotensin-converting enzyme gene polymorphisms and exercise performance in patients with COPD

Background and objective:   Recent studies have shown that polymorphisms of the angiotensin-converting enzyme (ACE) gene are closely associated with pulmonary disorders. The ACE gene is involved in the regulation of inflammatory reactions to lung injury, respiratory drive, erythropoiesis and tissue oxygenation. The hypothesis for this study was that the ACE gene may be associated with the ventilatory response to exercise and the aerobic work efficiency of skeletal muscle in patients with COPD.
Methods:   Sixty-one Chinese Han COPD patients and 57 healthy control subjects performed incremental cardiopulmonary exercise testing on a cycle ergometer. ACE genotypes were determined using PCR amplification.
Results:   Resting lung function and blood gas index were not significantly different among the three ACE genotype COPD groups. Similarly, there were no significant differences in AT, maximal O₂ uptake, maximal O₂ pulse, maximal dyspnoea index, ventilatory response (ΔVE/ΔVCO₂), O₂ cost of ventilation (VO₂/W/VE), end-tidal partial pressure of carbon dioxide at maximal exercise and maximal SaO₂ among the three ACE genotype COPD patients. Maximal work load and aerobic work efficiency were higher in the COPD group with the II genotype than in those with the ID or DD genotype. There were no significant differences in resting lung function and cardiopulmonary exercise testing parameters among the three ACE genotype control groups.
Conclusions:   The ACE gene may be involved in the regulation of skeletal muscle aerobic work efficiency, but is not associated with the ventilatory responses to exercise in COPD patients.     

Cough-reflex sensitivity to inhaled capsaicin in COPD associated with increased exacerbation frequency

Background and objective:   The causes of exacerbations in COPD patients are poorly understood. This study examined the association between cough-reflex sensitivity in patients with stable COPD and the frequency of subsequent exacerbations.
Methods:   The sampling frame for cases and controls for this study was patients attending a hospital outpatient clinic. cough-reflex sensitivity was evaluated using the log concentration of capsaicin causing five or more coughs (log C₅). Subsequent COPD exacerbations were identified prospectively via symptom-based diaries over a 12-month period.
Results:   The study group comprised 45 COPD subjects and 10 controls. Mean log C₅ was lower in the COPD group than in the control group (0.97 (95% confidence interval (CI): 0.76–1.18) versus 1.26 (95% CI: 0.81–1.71), P  = 0.095). In the COPD group, log C₅ was negatively correlated with serum CRP level ( r  = −0.36, P  = 0.02) and significantly associated with the exacerbation frequency ( r  = −0.38, P  = 0.01). Stepwise multiple regression analysis showed that cough-reflex sensitivity was significantly associated with exacerbation frequency ( r ² = 0.15, P  = 0.01).
Conclusions:   Hypersensitivity of the cough reflex to inhaled capsaicin might reflect airway inflammation in stable COPD patients, which predisposes to frequent exacerbations.     

Preoperative use of inhaled tiotropium in lung cancer patients with untreated COPD

Background and objective:   Lung cancer patients with COPD are at high risk during surgery. Tiotropium, a long-acting bronchodilator, is a preferred maintenance therapy for COPD, but its efficacy in the perioperative period has not been clarified.
Methods:   A retrospective review was performed of the medical records of 102 patients with primary lung cancer and COPD, who underwent scheduled surgery. Twenty-one lung cancer patients with untreated mild-to-severe COPD received tiotropium preoperatively. Spirometry was performed prior to and after 2 weeks of treatment with tiotropium, and at 3 months after surgery.
Results:   Two-week preoperative treatment with tiotropium significantly improved respiratory symptoms and pulmonary function as reflected by FVC (median 3.43 L pretreatment vs 3.52 L post-treatment), FEV₁ (median 2.06 L vs 2.32 L) and FEV₁% (73.2% vs 81.0%) (all P  < 0.001). Postoperative FEV₁% was significantly increased from a median of 56.0% (interquartile range 51.6–60.3) to 63.4% (60.8–66.0) ( P  < 0.001). The increase in FEV₁ was inversely associated with severity of COPD ( r  = −0.59, P  < 0.005). Lung resections were successfully accomplished without complications. The postoperative FEV₁ predicted prior to tiotropium treatment was underestimated (median predicted postoperative FEV₁ 1.65 L vs median measured postoperative FEV₁ 1.96 L, P  < 0.001).
Conclusions:   Preoperative treatment with tiotropium may facilitate surgical treatment for lung cancer patients with COPD. This is encouraging for COPD patients who may require curative lung resections.     

Inflammatory markers in exhaled breath condensate from patients with asthma

Background and objective:   Evaluation of airway inflammation is important for the diagnosis and treatment of asthma. Exhaled breath condensate (EBC) is a minimally invasive method for assessing inflammation and may be useful for monitoring airway inflammation in asthma. The aims of this study were to establish an EBC collection method, to assess biomarkers reflecting asthmatic airway inflammation, and to determine the relationship of these biomarkers with asthma severity and lung function.
Methods:   Fifty-eight non-smoking healthy subjects, seven asymptomatic smokers, nine subjects with common cold and 55 asthmatics with disease severity ranging from mild intermittent to severe persistent were studied. The efficacy of a pipette method was compared with that of a commercial collecting device. pH, CRP, albumin, hydrogen peroxide (H₂O₂) and nitrite/nitrate levels were measured in EBC.
Results:   Except for the quantity of EBC collected and albumin levels, there were no differences between the commercial method and the pipette method in levels of biomarkers measured. Levels of CRP, H₂O₂ and nitrite/nitrate were significantly higher in the asthma group than that in the control group. In terms of asthma severity, pH and levels of CRP, H₂O₂ and nitrate were significantly higher in the mild persistent group than that in the other groups. In addition, H₂O₂ levels in EBC correlated significantly with the level of nitrite/nitrate. FEV₁ and PEF showed significant negative correlations with H₂O₂ and nitrite/nitrate levels.
Conclusion:   Measurement of EBC biomarkers is a non-invasive and useful way to evaluate airway inflammation in patients with asthma.     

Fecal Hydrogen Sulfide Production in Ulcerative Colitis

Objective: Sulfide, a product of sulfate-reducing bacteria, has been proposed to play an etiologic role in ulcerative colitis. Ulcerative colitis feces have increased numbers and activity of sulfate-reducing bacteria, but only modestly increased sulfide. However, fecal sulfide exists largely in the volatile, highly toxic H₂S form that moves rapidly from feces to surrounding gas. Our aim was to quantify the fecal release of H₂S and other volatiles (CO₂, H₂, CH₂, methanethiol, and dimethylsulfide).
Methods: Fecal samples from 25 subjects with ulcerative colitis and 17 controls were incubated in 4-L containers, and gas release was assessed at intervals over 24 h.
Results: H₂S release by ulcerative colitis feces was elevated 3–4-fold at every measurement point compared with normal feces (   p < 0.003  at 24 h). The only other significant difference was increased CO₂ release by ulcerative colitis feces at 1 h. Supplementation of fecal homogenates with sulfur-containing substrates showed that organic compounds (mucin, cysteine, taurocholate) provided more readily utilizable substrate for H₂S production than did sulfate.
Conclusions: Increased H₂S release is a relatively localized metabolic aberration of ulcerative colitis feces. This increased H₂S may reflect abnormalities of the fecal bacteria and/or substrate availability.     

Association between CRHR1 polymorphism and improved lung function in response to inhaled corticosteroid in patients with COPD

Background and objective:   Inhaled corticosteroids are used to treat COPD and asthma. An association between sequence variants in the corticotrophin-releasing hormone receptor 1 ( CRHR1 ) gene and improved lung function in asthmatics treated with inhaled corticosteroids was reported recently. This study investigated the association between the change in lung function in response to inhaled corticosteroids and single-nucleotide CRHR1 polymorphisms in patients with COPD.
Methods:   COPD patients ( n  = 87) with a positive smoking history were recruited from the pulmonary clinics of 11 hospitals in Korea. Patients were treated with fluticasone propionate and salmeterol for 12 weeks and lung function was measured at baseline and after the 12-week treatment. Eighty-four of the 87 subjects were successfully genotyped.
Results:   Seventy-one patients with the wild-type GG genotype and 13 patients with the heterozygous GT genotype in rs242 941 were evaluated. After 12-week treatment, the change in FEV₁ was significantly higher in patients with wild-type GG genotype (6.0 ± 0.8% of predicted FEV₁) than in GT heterozygotes (−0.8 ± 1.8, P  = 0.003).
Conclusions:   Improved FEV₁ following inhaled corticosteroid and a long-acting β2-agonist was associated with CRHR1 genetic polymorphism in patients with COPD.     

Acidosis and raised norepinephrine levels are associated with exercise dyspnoea in idiopathic pulmonary fibrosis

Background and objective:   Exertional dyspnoea limits patients with IPF in their activities of daily living. The mechanism, however, has not been elucidated. This study tested the hypothesis in IPF that exertional dyspnoea correlates with cardiopulmonary exercise responses, specifically changes in arterial blood pH and plasma norepinephrine (NE).
Methods:   Cardiopulmonary exercise testing with measurements of dyspnoea (Borg scale), plasma NE, plasma lactate and arterial blood gases were performed in 29 patients with IPF and in nine controls.
Results:   Both groups showed obvious break points in dyspnoea changes during exercise. In IPF, an abrupt change in the Borg scale, pH, PaCO₂ and plasma NE occurred in the late exercise phase after the 'break point'. Compared with controls, patients with IPF had significantly higher HCO₃^- levels and physiologic dead space/tidal volume during exercise. In IPF, during both exercise phases, the dyspnoea slope (ΔBorg scale/Δminute ventilation) correlated with the pH slope (ΔpH/Δoxygen uptake) (before the break point: r  = −0.537, P  = 0.0022; r  = −0.886, P  < 0.0001, after the break point) and the NE slope (ΔNE/Δoxygen uptake) (before the break point: r  = 0.481, P  = 0.0075; R  = 0.784, P  < 0.0001, after the break point).
Conclusions:   In patients with IPF, exercise-induced acidosis and increases in circulating NE levels were associated with intensity of exertional dyspnoea.     

Association of beta-2-adrenoceptor polymorphisms and pulmonary function in patients with chronic obstructive pulmonary disease

Aims:   The Dutch Hypothesis suggests that asthma and chronic obstructive pulmonary disease may share some pathogenic mechanisms. There is considerable evidence that polymorphisms of the β₂ adrenoceptor have disease-modifying roles in juvenile onset asthma, determining severity and response to β agonists, but not determining disease susceptibility. There is evidence from family and twin studies to suggest that chronic obstructive pulmonary disease (COPD) also has a significant genetic component. We therefore hypothesized that β₂ adrenoceptor polymorphisms would have similar disease modifying roles in patients with COPD.
Methods:   One hundred and ninety-five COPD subjects and 142 matched controls were recruited. All had detailed clinical phenotyping. Subjects were genotyped for the Agr → Gly polymorphism at codon 16, the Gln → Glu polymorphism at codon 27, and the SNPC/T-47 promoter polymorphism.
Results:   In patients with COPD (mean age 67, 57% male), individuals with the homozygous Gly16/homozygous Glu27/homozygous SNP −47*C genotype had significantly worse lung function as measured by forced expiratory volume 1, expressed as a percentage of its predicted value (39.2 compared with 45.8, P  = 0.004), and for forced vital capacity (FVC) percent predicted (77.2 compared with 70.4, P  = 0.02). The polymorphisms had no effect on disease susceptibility.
Conclusion:   The Arg16, Gln27, SNPC/T-47 β₂ adrenoceptor polymorphisms may have disease modifying roles in patients with COPD.     

Longitudinal study of airway dimensions in chronic obstructive pulmonary disease using computed tomography

Background and objective:   Chest CT has been widely used for the evaluation of structural changes in lung parenchyma and airways in cross-sectional studies. There has been no report on the annual changes in airway dimensions as assessed by CT in COPD patients. The objective of this study was to investigate the annual changes in airway dimensions and lung attenuation using CT in patients with COPD and to evaluate the correlations among annual changes in CT measurements and pulmonary function.
Methods:   Eighty-three men with COPD had completed five annual assessments of CT scans and pulmonary function tests over 4 years. Airway dimensions of the basal segment bronchi and lung attenuation on CT images were analysed in 38 subjects in whom the same airway could be measured at least three times, including at entry and at the end of the study.
Results:   Mean annual decline in FEV₁ was 21 mL/year. Annual changes in the percentage of low attenuation areas were not significantly correlated with decline in FEV₁. On the other hand, annual changes in the percentage of wall area (WA%/year) were significantly inversely correlated with annual changes in FEV₁ ( r  = −0.363, P  = 0.025), whereas WA%/year did not differ among severity stages at entry and did not correlate with baseline FEV₁.
Conclusions:   The results showing that annual changes in airway thickening correlated with annual decline in air flow limitation suggests the importance of treatment of airway inflammation in COPD. CT is a useful tool for quantitative estimation not only of emphysema but also of airway lesions in longitudinal studies.     

The efficacy and applicability of a pulmonary rehabilitation programme for patients with COPD in a secondary-care community hospital

Background and objective:   Pulmonary rehabilitation is known to have beneficial effects in COPD patients. This study aimed to assess the applicability and efficacy of a pulmonary rehabilitation programme in a community hospital lacking specialist pulmonary rehabilitation services.
Methods:   This randomized, controlled, prospective study included a total of 78 patients. Questionnaires were used to collect data on sociodemographic characteristics, respiratory function tests, the Modified Medical Research Council dyspnoea scale, 6MWD, the Short Form-36 (SF-36) quality of life scale, the Hospital Anxiety and Depression Scale (HADS) and the St George's Respiratory Questionnaire (SGRQ). The experimental group underwent a pulmonary rehabilitation programme while the control group did not participate. The first, second and third month measurements for all parameters were compared between the two groups.
Results:   No significant differences in pulmonary function tests or dyspnoea scale ( P  > 0.05) were observed between the two groups. Significant differences were observed in the 6MWD measurements at the third month ( P  < 0.05), as well as in the SF-36 quality of life scale, SGRQ and HADS measurements at the second and third months ( P  < 0.01).
Conclusions:   Short-term pulmonary rehabilitation had a positive impact on exercise capacity and quality of life of patients with COPD, irrespective of FEV₁. This study demonstrated the efficacy of a pulmonary rehabilitation programme in a secondary care hospital not staffed by a specialist pulmonary rehabilitation group.     

Protein malnutrition in elderly patients with chronic obstructive pulmonary disease

Background: It has been suggested that hypermetabolism or reduction of total caloric intake or a combination of both conditions occur in malnourished patients with chronic obstructive pulmonary disease (COPD). It is hypothesized that protein malnutrition plays a role in the metabolism of malnourished elderly COPD patients.
Methods: Thirteen COPD patients (mean age: 75.7 years) with severe obstructive ventilatory disorder were divided into two groups: body mass index greater than 20 (group N; n  = 8) and less than 20 (group L; n  = 5). A nutritional survey and metabolic study were performed.
Results: Energy balances appeared more highly positive in group L than in group N and serum concentrations of total protein, albumin and transferrin tended to be lower in group L than in group N (all showed no statistically significant difference). The mean protein digestibility did not show any significant difference between the two groups, suggesting that group L subjects digested and absorbed the ingested dietary protein normally. Mean nitrogen balance was more highly positive in group L than in group N. The FEV₁ decreased significantly with increases in the basal metabolic rate (BMR), total daily energy expenditure and urinary nitrogen excretion, respectively (all P  < 0.05). PaO₂ was positively and significantly correlated with serum concentrations of albumin and transferrin ( P  = 0.001 and P  < 0.05), respectively. Body mass index (BMI) was negatively correlated with BMR ( P  < 0.05).
Conclusions: It is suggested that malnourished COPD patients with lower BMI showed enhanced protein and energy metabolism. Thus, it is likely that malnourished elderly COPD patients could improve through not only supplementation of total carolic intake but also sufficient protein intake.     

Stephania tetrandra prevents and regresses liver fibrosis induced by carbon tetrachloride in rats

Background and Aim:  There is currently no safe and effective treatment for liver fibrosis. We have previously shown that Stephania tetrandra ( ST ) and Salvia miltiorrhiza ( SM ) suppress cell proliferation and enhance apoptosis of hepatic stellate cell (HSC) in vitro . In this study, we aimed to investigate the anti-fibrotic effect of these two herbs in vivo .
Methods:  Liver fibrosis was induced by carbon tetrachloride (CCl₄) injection in rats for 5 weeks. SM , ST or SM  +  ST was gavaged on day 1 of CCl₄ administration to study the preventive effects of herbs on hepatic fibrosis. In a separate study designed to assess possible fibrosis regression, rats were randomly allocated to be treated with SM, ST or SM  +  ST when fibrosis was established. Liver injury and collagen content were assessed. HSC activation and apoptosis were determined.
Results:  As compared with the CCL₄-only rats, serum ALT was significantly lower in CCl₄-treated rats that received either SM ( P  < 0.01) or ST ( P  < 0.01). Administration of ST significantly prevented ( P  < 0.01) or reversed the hepatic fibrosis ( P  < 0.01) induced by CCL₄. Moreover, rats treated with ST had reduced protein expression of α-SMA both in prevention ( P  < 0.05) and in regression ( P  < 0.01) experiments. The double-color staining of α-SMA and TUNEL showed that ST increased HSC apoptosis. However, co-treatment of SM  +  ST did not increase the antifibrotic effect of ST .
Conclusions:  Stephania tetrandra safely and effectively prevents and reverses hepatic fibrosis through activating HSC apoptosis in rats.     

Risk factors for high cerebral blood flow velocity and death in Kenyan children with Sickle Cell Anaemia: role of haemoglobin oxygen saturation and febrile illness

High cerebral blood flow velocity (CBFv) and low haemoglobin oxygen saturation (SpO₂) predict neurological complications in sickle cell anaemia (SCA) but any association is unclear. In a cross-sectional study of 105 Kenyan children, mean CBFv was 120 ± 34·9 cm/s; 3 had conditional CBFv (170–199 cm/s) but none had abnormal CBFv (>200 cm/s). After adjustment for age and haematocrit, CBFv ≥150 cm/s was predicted by SpO₂ ≤ 95% and history of fever. Four years later, 10 children were lost to follow-up, none had suffered neurological events and 11/95 (12%) had died, predicted by history of fever but not low SpO₂. Natural history of SCA in Africa may be different from North America and Europe.     

Carbocisteine can scavenge reactive oxygen species in vitro

Background and objective:   Reactive oxygen species (ROS) play an important role in the pathogenesis of various respiratory diseases. Carbocisteine, a mucoregulatory drug, is used in the treatment of several disease states but little information is available about its scavenger effects on ROS. The present study was designed to examine the scavenger effects of carbocisteine on ROS.
Methods:   The oxidation-reduction potential of carbocisteine was measured, and its scavenger effects on hypochlorous acid (HOCl), hydrogen peroxide (H₂O₂), hydroxyl radical (OH^•) and peroxynitrite (ONOO^-) were examined in cell-free conditions. The effects of carbocisteine on ROS generated from rat neutrophils, intracellular oxidative stress and release of inflammatory cytokines (IL-8 and IL-6) from IL-1β-induced airway epithelial cells, NCI-H292 cells, were investigated.
Results:   Carbocisteine provided a reducing stage and showed scavenger effects on H₂O₂, HOCl, OH^• and ONOO^- in cell-free conditions. Carbocisteine inhibited ROS generation from rat neutrophils, intracellular oxidative stress and release of IL-8 and IL-6 from NCI-H292 cells. N -acetyl- l -cysteine, a radical scavenger, also inhibited these events related to ROS as well as carbocisteine.
Conclusions:   These results suggest that carbocisteine could exert anti-inflammatory and anti-oxidant effects through directly scavenging ROS in addition to its previously known mucoregulatory effect.     

Airway responses to salbutamol after exposure to chemical warfare

Background and objectives:   Increased airway responsiveness to β-agonists is noted in asthmatics and smokers. The lung may be exposed to chemical warfare agents such as mustard gas and pulmonary complications of exposure range from no effect to severe bronchial stenosis. There is little understanding of airway hyperresponsiveness to β-agonist drugs in chemical war victims and this study examined airway responsiveness to salbutamol in victims of chemical warfare.
Methods:   The threshold concentrations of inhaled salbutamol required for a 20% change in FEV₁ as PC₂₀, or a 35% change in specific airway conductance (sGaw) as PC₃₅ were measured in 22 persons exposed to chemical warfare and 15 normal control subjects.
Results:   In 11 of the 22 subjects PC₂₀ salbutamol could be measured and in 15 of the 22 subjects PC₃₅ salbutamol could be measured. This group of patients was the responder group (PC₂₀ = 10.79 and PC₃₅ = 8.55 mg/L) and in them the concentration of salbutamol needed for a response was significantly lower than that required in normal controls (PC₂₀ = 237.68 and PC₃₅ = 88.72 mg/L, P  < 0.001). There was a significant correlation between FEV₁ and PC₂₀ salbutamol ( r  = 0.815, P  < 0.001).
Conclusions:   These results showed increased airway responsiveness to salbutamol in most subjects exposed to chemical warfare; this was correlated with airway calibre.     

Dual-energy X-ray absorptiometry is the method of choice to assess body composition in COPD

Background and objective:   Mortality and morbidity in COPD have been related to reduced FEV₁ as well as indices of body composition. Different techniques used to evaluate body composition may vary in accuracy, particularly in conditions with altered fluid balance such as COPD. We hypothesized that direct measurement of fat-free mass index (FFMI) by dual-energy X-ray absorptiometry (DEXA) would provide superior assessment of body composition in COPD.
Methods:   We measured body composition in 31 patients with COPD randomly selected from a teaching hospital clinic. To estimate total body water (TBW) and FFMI, skin-fold anthropometry, bioelectrical impedance analysis (BIA) with Schols and Lukaski equations as well as DEXA, total body potassium by whole-body γ-counting (TBK) and in vivo neutron activation analysis were used. Combined body composition methods providing precise estimations of TBW were used for comparisons. Bland–Altman analyses, ANOVA and χ²-testing were used to examine data.
Results:   Mean BMI was 27.6 ± 5.34 kg/m² (mean ± SD). Estimations of TBW were similar using Schols BIA or by using combined body composition methods. FFMI did not vary significantly between grades of COPD severity but was significantly different when assessed using DEXA and other methods. Calculated FFM hydration was significantly different from the fixed hydration factor used to calculate FFMI from BIA TBW ( P  < 0.05).
Conclusion:   The Schols BIA method incorporates a fixed hydration factor that may lead to an erroneous estimation of FFMI with ensuing clinical implications. DEXA can be used to obtain accurate and comprehensive assessments of body composition and should be the preferred investigation in COPD.     

Determinants of cardiorespiratory fitness in patients with chronic obstructive pulmonary disease, focusing on activities parallel to daily living

Objective:   The purpose of this study was to examine whether activities parallel to daily living (APDL) constitute a determinant index of cardiorespiratory fitness in patients with chronic obstructive pulmonary disease (COPD).
Methodology:   Four functional physical fitness parameters were investigated in 38 male patients (mean age 69.8 ± 6.7 years) with moderate to severe COPD. The parameters measured were muscular strength (grip strength), muscular endurance strength (arm curl, keeping a half-squat position) and regulation (walking around two cones). In addition, cardiorespiratory fitness was measured using a 6-min walking distance test (6MWD) and peak oxygen uptake (VO_2peak) was measured during bicycle ergometer testing. Maximal inspiratory pressure (MIP) and maximal expiratory pressure were measured so as to quantify respiratory muscle strength.
Results:   There were significant correlations ( P  < 0.05) between the VO_2peak, muscular endurance, pulmonary function and respiratory muscle strength. There were also significant correlations of VO_2peak to muscular endurance, muscular strength, muscular endurance strength and regulation. In stepwise multiple regression analysis, per cent predicted forced expiratory volume in 1 s and MIP appeared to be significant determinants of VO_2peak, showing a total variance of 56% ( P  < 0.05). For the 6MWD, the significant determinants were forced vital capacity, MIP and performance in the half-squat test, showing a variance of 59% ( P  < 0.05).
Conclusion:   The results suggest that cardiorespiratory fitness is strongly affected by MIP, pulmonary function and muscular endurance strength, as APDL depend on lower-limb use.     

Neutrophil elastase activity in acute lung injury and respiratory distress syndrome

Background and objective:   Neutrophil elastase (NE) may play a key role in the development of acute lung injury (ALI) or ARDS. NE activity (NEA) was measured in patients with ALI treated with a selective NE inhibitor.
Methods:   NEA and NE-α1-antitrypsin (NE-AT) complex were measured in plasma before, during and after the administration of the selective NE inhibitor, sivelestat, in 32 patients with a diagnosis of ALI or ARDS. NEA index (NEAI) was calculated as NEA/NE-AT. The sequential organ failure assessment (SOFA) score and the ratio PaO₂/fraction of inspired oxygen (FiO₂) were measured.
Results:   NEA and NE-AT was raised in all patients. Sivelestat reduced NEAI and NEA ( P  < 0.01 for both) but not NE-AT and NEA, and NEAI returned to pretreatment levels. NEA correlated closely with NE-AT before, but not after treatment. No relationship was observed between these indices and SOFA score or PaO₂/FiO₂ ratio.
Conclusions:   Sivelestat reduced NEA and NEAI in patients with ALI or ARDS suggesting NE inhibition. A larger study is needed to determine the relationship of NEA, NE-AT and NEAI with the outcome of ALI/ARDS.