A multivariate analysis of serum nutrient levels and lung function

<p>Abstract</p> <p>Background</p> <p>There is mounting evidence that estimates of intakes of a range of dietary nutrients are related to both lung function level and rate of decline, but far less evidence on the relation between lung function and objective measures of serum levels of individual nutrients. The aim of this study was to conduct a comprehensive examination of the independent associations of a wide range of serum markers of nutritional status with lung function, measured as the one-second forced expiratory volume (FEV₁).</p> <p>Methods</p> <p>Using data from the Third National Health and Nutrition Examination Survey, a US population-based cross-sectional study, we investigated the relation between 21 serum markers of potentially relevant nutrients and FEV₁, with adjustment for potential confounding factors. Systematic approaches were used to guide the analysis.</p> <p>Results</p> <p>In a mutually adjusted model, higher serum levels of antioxidant vitamins (vitamin A, beta-cryptoxanthin, vitamin C, vitamin E), selenium, normalized calcium, chloride, and iron were independently associated with higher levels of FEV₁. Higher concentrations of potassium and sodium were associated with lower FEV₁.</p> <p>Conclusion</p> <p>Maintaining higher serum concentrations of dietary antioxidant vitamins and selenium is potentially beneficial to lung health. In addition other novel associations found in this study merit further investigation.</p

Systematic review with meta-analysis of the epidemiological evidence relating smoking to COPD, chronic bronchitis and emphysema

<p>Abstract</p> <p>Background</p> <p>Smoking is a known cause of the outcomes COPD, chronic bronchitis (CB) and emphysema, but no previous systematic review exists. We summarize evidence for various smoking indices.</p> <p>Methods</p> <p>Based on MEDLINE searches and other sources we obtained papers published to 2006 describing epidemiological studies relating incidence or prevalence of these outcomes to smoking. Studies in children or adolescents, or in populations at high respiratory disease risk or with co-existing diseases were excluded. Study-specific data were extracted on design, exposures and outcomes considered, and confounder adjustment. For each outcome RRs/ORs and 95% CIs were extracted for ever, current and ex smoking and various dose response indices, and meta-analyses and meta-regressions conducted to determine how relationships were modified by various study and RR characteristics.</p> <p>Results</p> <p>Of 218 studies identified, 133 provide data for COPD, 101 for CB and 28 for emphysema. RR estimates are markedly heterogeneous. Based on random-effects meta-analyses of most-adjusted RR/ORs, estimates are elevated for ever smoking (COPD 2.89, CI 2.63-3.17, n = 129 RRs; CB 2.69, 2.50-2.90, n = 114; emphysema 4.51, 3.38-6.02, n = 28), current smoking (COPD 3.51, 3.08-3.99; CB 3.41, 3.13-3.72; emphysema 4.87, 2.83-8.41) and ex smoking (COPD 2.35, 2.11-2.63; CB 1.63, 1.50-1.78; emphysema 3.52, 2.51-4.94). For COPD, RRs are higher for males, for studies conducted in North America, for cigarette smoking rather than any product smoking, and where the unexposed base is never smoking any product, and are markedly lower when asthma is included in the COPD definition. Variations by sex, continent, smoking product and unexposed group are in the same direction for CB, but less clearly demonstrated. For all outcomes RRs are higher when based on mortality, and for COPD are markedly lower when based on lung function. For all outcomes, risk increases with amount smoked and pack-years. Limited data show risk decreases with increasing starting age for COPD and CB and with increasing quitting duration for COPD. No clear relationship is seen with duration of smoking.</p> <p>Conclusions</p> <p>The results confirm and quantify the causal relationships with smoking.</p

Effects of inhaled steroids on methacholine-induced bronchoconstriction and gas trapping in mild asthma.

According to a recent hypothesis, airway smooth muscle regulates airway calibre mostly at high lung volume, whereas the mucosa and adventitia dimensions dominate at low lung volumes. It was thought that if inhaled steroids decrease the thickness of airway wall in asthma, then forced vital capacity (FVC), which reflects the functional changes at low lung volume, should decrease less during induced bronchoconstriction than flow at high volume. The study was conducted in 31 mild asthmatics under control conditions and during a methacholine challenge before and after 4-weeks treatment with inhaled fluticasone dipropionate (1.5 mg daily, 16 patients) or placebo (15 patients). After fluticasone dipropionate treatment, control forced expiratory volume in one second (FEV1), and maximal flow at 50% of control FVC during forced expiration after a maximal (V'max,50) and a partial inspiration (V'p,50) significantly increased. During methacholine challenge, FVC decreased less than did FEV1 or V'max,50, and so did inspiratory vital capacity compared to V'p,50. Both the provocative dose of methacholine causing a 20% fall in FEV1 and the bronchodilator effect of deep inhalation significantly increased. The latter was assessed by means of the regression coefficient of all V'max,50 plotted against V'p,50. No significant changes in these parameters occurred after placebo. These data show that inhaled steroids remarkably blunt the occurrence of gas trapping during induced bronchoconstriction in mild bronchial asthma, possibly due to their effect on airway wall remodelling

International variations in asthma treatment compliance: the results of the European Community Respiratory Health Survey (ECRHS)

Noncompliance to medication is a major barrier to effective asthma management. Its real extent and geographical variation throughout the world are not yet known. The data on compliance, collected in the framework of the European Community Respiratory Health Survey (ECRHS) on 1771 subjects (aged 20-44 yrs) with current asthma identified in 14 countries, offer a unique opportunity to assess the extent of noncompliance and its variation across countries. The median percentage of current asthmatics who had received a medical prescription at least once was 95%. The compliance of those patients who had received a medical prescription was found to be low in all countries (median 67%) but with wide variations, the rate ranging from 40% (USA) to 78% (Iceland). During exacerbations patients' rate of compliance increased to 72%. Age was the only variable which influenced compliance to treatment. A significant, although weak, negative correlation was found between patients' compliance and rate of hospital casualty department or emergency room admissions. This study documents that compliance to the treatment of asthma is poor worldwide and that there are large variations between countries. These results emphasize the necessity for further efforts to improve patients' education and to promulgate the international guidelines

Lung function in survivors of childhood acute lymphoblastic leukemia

Study objectives: To evaluate lung function in patients cured from childhood acute lymphoblastic leukemia (ALL) with chemotherapy alone or plus bone marrow transplantation (BMT). Pulmonary toxicity is a well-recognized side effect of many ALL treatments. Design: Cross-sectional study conducted at least 3 years after cessation of therapy. Setting: Outpatient pneumology department of the University Hospital. Patients: Forty-four subjects (age range at observation, 6 to 23 years): 21 treated only with intensive Berlin-Frankfurt-Munster (BFM)-type chemotherapy for newly diagnosed ALL (group A), and 23 treated with chemotherapy plus BMT (group B). Measurements: A detailed history of smoking habit, respiratory symptoms, and diseases was recorded directly from the patients with the aid of their parents. A complete physical examination and lung function testing (lung volumes and diffusion capacity for carbon monoxide [DLCO]) were performed in all subjects. Results: No patient reported acute or chronic respiratory symptoms or diseases. In group A patients, lung function was in the normal range, except for three subjects in whom there was an isolated impairment of DLCO. In group B patients, lung function was markedly impaired, with more than half the patients having an abnormal DLCO. A statistically significant difference was found between the two groups for FVC (p 5 0.022) and DLCO (p 5 0.004). Conclusions: Intensive, BFM-type frontline chemotherapy is not associated with late pulmonary dysfunction; however, retreatment including BMT can frequently injure the lung. Thus, in patients who undergo BMT and whose life expectancy is long, careful monitoring of lung function and counseling about avoiding additional lung risk factors is recommended

Lung cancer resection: the prediction of postsurgical outcomes should include long-term functional results.

STUDY OBJECTIVES: To assess (1) the possibility of predicting long-term postoperative lung function, and (2) the usefulness of maximal oxygen consumption (O(2)max) as a criterion for operability and as a predictor of long-term disability. DESIGN: Prospective study. SETTING: Outpatients and inpatients of a university hospital. PARTICIPANTS: Sixty-two consecutive patients (mean +/- SD age, 62 +/- 8 years; 51 male and 11 female patients) were preoperatively evaluated for lung cancer resection (pneumonectomy or bilobectomy [n = 14] and lobectomy [n = 48]). MEASUREMENTS: Clinical examination and recorded respiratory symptoms and spirometry results before surgery and 6 months after surgery. If predicted postoperative FEV(1) (ppoFEV(1)) was < 40%, patients underwent exercise testing; if O(2)max was between 10 mL/kg/min and 20 mL/kg/min, patients underwent a split-function study. RESULTS: All the patients with ppoFEV(1) > or = 40%-even those patients (26%) with FEV(1) < 80%-underwent thoracotomy without further tests. Seven patients with ppoFEV(1) < 40% underwent exercise testing, and three of them underwent a split-function study. Nine patients (15%; including six patients with COPD and one patient with asthma) had immediate postoperative complications (pneumonia [n = 5] and respiratory failure [n = 4]); seven of these patients had ppoFEV(1) > or = 40%. ppoFEV(1) significantly underestimated the actual postoperative FEV(1) (poFEV(1); p < 0.001) 6 months after pneumonectomy or bilobectomy but was reliable for actual poFEV(1) after lobectomy. Two patients with predicted postoperative O(2)max > 10 mL/kg/min became oxygen dependent and had marked limitation of daily living. CONCLUSIONS: ppoFEV(1) > or = 40% reliably identifies patients not requiring further tests and not at long-term risk of respiratory disability. O(2)max, effective for defining the immediate surgical risk, is not useful in predicting long-term disability