Cough threshold in patients with chronic obstructive pulmonary disease.
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BACKGROUND: Cough is an important symptom of patients with chronic obstructive pulmonary disease (COPD). The cough threshold to citric acid and capsaicin in patients with COPD and in normal volunteers was measured, as well as bronchial hyperresponsiveness to methacholine. METHODS: Nineteen patients with COPD and 22 controls were recruited. Subjects underwent a methacholine bronchoprovocation test and a cough challenge to citric acid and capsaicin. RESULTS: The log citric acid cough threshold D2 (concentration causing two coughs) was significantly lower in patients with COPD (mean 2.17 versus 2.56, mean difference (95% CI) 0.39 (0.04 to 0.74), p = 0.02) but not for capsaicin cough D2 (0.66 versus 0.8, p = 0.41). Sixteen patients with COPD had bronchial hyperresponsiveness which was correlated with baseline FEV1 (r = 0.6, p = 0.01, 95% CI 0.15 to 0.84). CONCLUSIONS: Patients with COPD have a lower cough threshold to citric acid, possibly due to a differential effect of cigarette smoke on citric acid sensitive cough receptors. (+info)
Prevalence of depression in patients with chronic obstructive pulmonary disease: a systematic review.
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BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) have repeatedly been characterised as a population of chronically ill patients with a higher than normal prevalence of depression. Susceptibility for depression has been noted in patients with certain other chronic conditions. This systematic review was conducted to achieve a more definite answer to the question: do patients with COPD show a higher than normal prevalence of depression? METHODS: Studies in English language journals were retrieved by an electronic search over the period from 1966 to December 1997 and by an extended search of reference lists, and were included or excluded according to a system of diagnostic and methodological criteria. RESULTS: Ten studies were included, of which only four had a case-control design. Three of the case-control studies reported an increased prevalence of depression among patients with COPD which was statistically significant in only one. The fourth controlled study found a significantly increased depression score among COPD patients. Of the remaining six uncontrolled studies three found a high baseline prevalence of depression among their study group. CONCLUSIONS: An association between COPD and depression was found in the four controlled studies. The two methodologically best conducted studies that did not detect a statistically significant higher prevalence lacked power. The two studies that did find a significant association used a questionable depression measure. The prevalence of depression was high compared with general population figures in three of six non-controlled studies. The empirical evidence for a significant risk of depression in patients with COPD remains inconclusive, due to the poor methodological quality of most of the published studies, the lack of studies with an adequate sample size, and variability in instruments and cut off scores used to measure depression. (+info)
Glutathione S-transferase P1 (GSTP1) polymorphism in patients with chronic obstructive pulmonary disease.
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BACKGROUND: Enzymes that contribute to the local detoxification in alveoli and bronchioles have an important role in the defence mechanism against tobacco smoke. It has been suggested that genetic susceptibility to smoking injury may confer a risk for the development of chronic obstructive pulmonary disease (COPD). The polymorphisms in glutathione S-transferase P1 (GSTP1), a xenobiotic metabolising enzyme, were investigated in patients with COPD. METHODS: Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) were performed to genotype GSTP1 polymorphisms in exon 5 (Ile105Val) and exon 6 (Ala114Val). Blood samples were taken from 53 patients with COPD and 50 control subjects at the Tokyo University Hospital, the Juntendo University Hospital, and the Tokyo Kenbikyoin Clinic for use in the study. RESULTS: The proportion of GSTP1/Ile105 homozygotes was significantly higher in the patients with COPD than in the control subjects (79% vs 52%). The odds ratio for GSTP1/Ile105 homozygotes versus all other genotypes was 3.5 (95% CI 2.7 to 4.6) for COPD. Polymorphism at residue 114 of GSTP1 was not found in either group. CONCLUSIONS: Genetic polymorphism of exon 5 of GSTP1 may be associated with COPD because the GSTP1/Ile105 genotype is predominantly found in COPD. It is suggested that the GSTP1/Ile105 genotype may be less protective against xenobiotics in tobacco smoke. (+info)
Complexity of terminal airspace geometry assessed by lung computed tomography in normal subjects and patients with chronic obstructive pulmonary disease.
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Increases in the low attenuation areas (LAA) of chest x-ray computed tomography images in patients with chronic obstructive pulmonary disease (COPD) have been reported to reflect the development of pathological emphysema. We examined the statistical properties of LAA clusters in COPD patients and in healthy subjects. In COPD patients, the percentage of the lung field occupied by LAAs (LAA%) ranged from 2.6 to 67.6. In contrast, LAA% was always <30% in healthy subjects. The cumulative size distribution of the LAA clusters followed a power law characterized by an exponent D. We show that D is a measure of the complexity of the terminal airspace geometry. The COPD patients with normal LAA% had significantly smaller D values than the healthy subjects, and the D values did not correlate with pulmonary function tests except for the diffusing capacity of the lung. We interpret these results by using a large elastic spring network model and find that the neighboring smaller LAA clusters tend to coalesce and form larger clusters as the weak elastic fibers separating them break under tension. This process leaves LAA% unchanged whereas it decreases the number of small clusters and increases the number of large clusters, which results in a reduction in D similar to that observed in early emphysema patients. These findings suggest that D is a sensitive and powerful parameter for the detection of the terminal airspace enlargement that occurs in early emphysema. (+info)
The effect of passive smoking on pulmonary function during childhood.
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Passive smoking, especially of maternal origin, is known to influence adversely the development of children's pulmonary function. In this study, the effect of parental smoking on the pulmonary function of 360 primary school children aged 9-13 (mean 10.8 +/- 0.7) years was investigated. Information on parental smoking history was collected using a questionnaire, and spirometric measurements were performed on the children. All spirometric indices were lower in children who had been passively exposed to parental tobacco smoke than those not exposed. The percentage of households in which at least one parent smoked was 81.5%. This figure was significantly lower for mothers (27.5%) than for fathers (79%). Paternal smoking was associated with reduced levels of forced expiratory flow between 25-75% of vital capacity, peak expiratory flow, and flow rates after 50% and 75% of vital capacity expired (p < 0.05). Maternal smoking did not have statistically significant adverse effects on children's pulmonary function. This result might be due to the low occurrence of either pre- or post-natal smoking among mothers and confirms that, in our population, the main target group for antitobacco campaigns should be fathers. (+info)
Supine exercise restores arterial blood pressure and skin blood flow despite dehydration and hyperthermia.
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We determined whether the deleterious effects of dehydration and hyperthermia on cardiovascular function during upright exercise were attenuated by elevating central blood volume with supine exercise. Seven trained men [maximal oxygen consumption (VO(2 max)) 4.7 +/- 0. 4 l/min (mean +/- SE)] cycled for 30 min in the heat (35 degrees C) in the upright and in the supine positions (VO(2) 2.93 +/- 0.27 l/min) while maintaining euhydration by fluid ingestion or while being dehydrated by 5% of body weight after 2 h of upright exercise. When subjects were euhydrated, esophageal temperature (T(es)) was 37. 8-38.0 degrees C in both body postures. Dehydration caused equal hyperthermia during both upright and supine exercise (T(es) = 38. 7-38.8 degrees C). During upright exercise, dehydration lowered stroke volume (SV), cardiac output, mean arterial pressure (MAP), and cutaneous vascular conductance and increased heart rate and plasma catecholamines [30 +/- 6 ml, 3.0 +/- 0.7 l/min, 6 +/- 2 mmHg, 22 +/- 8%, 14 +/- 2 beats/min, and 50-96%, respectively; all P < 0. 05]. In contrast, during supine exercise, dehydration did not cause significant alterations in MAP, cutaneous vascular conductance, or plasma catecholamines. Furthermore, supine versus upright exercise attenuated the increases in heart rate (7 +/- 2 vs. 9 +/- 1%) and the reductions in SV (13 +/- 4 vs. 21 +/- 3%) and cardiac output (8 +/- 3 vs. 14 +/- 3%) (all P < 0.05). These results suggest that the decline in cutaneous vascular conductance and the increase in plasma norepinephrine concentration, independent of hyperthermia, are associated with a reduction in central blood volume and a lower arterial blood pressure. (+info)
Randomized trial of inhaled fluticasone propionate in chronic stable pulmonary sarcoidosis: a pilot study.
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Pulmonary sarcoidosis is a disease in which the pathological processes are distributed along lymphatic pathways, particularly those around the bronchovascular bundles. Delivery of disease-modulating drugs by the inhaled route is therefore an attractive option. The aim of this study was to determine the efficacy of inhaled fluticasone propionate 2 mg x day(-1) in adults with stable pulmonary sarcoidosis. Forty-four adult patients (22 from each centre) were enrolled from outpatient clinics in two London teaching hospitals in a two centre, double-blind, randomized, placebo-controlled trial. Primary end points were home recordings of peak expiratory flow rate (PEFR), forced expiratory volume in one second (FEV1), and forced vital capacity (FVC). Secondary end points were symptom scores, use of rescue bronchodilator medication, and clinic values for PEFR, FEV1, FVC, forced mid-expiratory flow (FEF25-75%), diffusion capacity of the lung for carbon monoxide (DL,CO), and total lung capacity (TLC). Symptom scores of cough, breathlessness and wheeze were lower in the active treatment group, but this did not reach statistical significance, and a general health perception assessment (Short Form (SF)-36) showed a difference between active and placebo treatment. No significant differences were found between the two groups in any physiological outcome measure. No new adverse reactions were detected. The results of this pilot study do not show an objective benefit of inhaled fluticasone propionate in pulmonary sarcoidosis where the disease is stable and is controlled without the use of inhaled corticosteroids. (+info)
Clinical and immunoregulatory effects of roxithromycin therapy for chronic respiratory tract infection.
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The clinical and immunoregulatory effects of long-term macrolide antibiotic therapy for patients with chronic lower respiratory tract infections (CLRTI) were investigated. Clinical parameters and neutrophil chemotactic mediators in the epithelial lining fluid (ELF) of CLRTI patients (n = 10) were examined before and after 3 months oral administration of roxithromycin (RXM). The in vitro effects of RXM were also examined on the release of these mediators from alveolar macrophages (AM) and neutrophils. Arterial oxygen tension (p<0.05), vital capacity (VC) (p<0.001), %VC (p<0.05) and forced expiratory volume in one second (p<0.01) were improved after RXM treatment, but airway bacteria were not eradicated. Among the mediators, the levels of interleukin (IL)-8, neutrophil elastase (NE) and leukotriene B4 (LTB4) were higher in ELF than in plasma of CLRTI patients and they decreased after RXM treatment (n = 7, p<0.05 for each). RXM concentrations were significantly increased in the bronchoalveolar lavage cells of the treated patients. In in vitro experiments, RXM showed inhibitory effects on IL-8 release from AM and neutrophils. In conclusion, interleukin-8, neutrophil elastase and leukotriene B4 contribute to the neutrophilic inflammation in the airways of chronic lower respiratory tract infection patients and the clinical effects of roxithromycin may, in part, be attributable to the suppression of excess release of the chemotactic mediators from inflammatory cells. (+info)