Forced Vital Capacity Ratio Research Articles

No relationship between lung function and high‐sensitive C‐reactive protein in adolescence

Several studies on adults have indicated that lower spirometric lung function may be associated with increased systemic inflammation, but no studies have investigated if this association is already present in adolescence. We explored the temporal relationship between changes in lung function and concentrations of plasma C-reactive protein (CRP) in a population-based cohort study at ages 14 and 20 years using a high-sensitivity CRP assay. CRP measurements were performed in a total of 420 subjects at mean age of 13.9 years. Of these, 262 subjects (62%) participated in the follow-up investigation at mean age of 20.1 years. Levels of log-CRP at age 14 were not significantly associated with forced expiratory volume (FEV(1) ) or FEV(1) / forced vital capacity (FVC) ratio at age 20, nor with the change in FEV(1) , FVC or FEV(1) /FVC ratio between 14 and 20 years after controlling for body mass index (BMI), airway hyperresponsiveness (AHR), eosinophil cationic protein (ECP), asthma, smoking, sex, and height at 14 years, and change in height between 14 and 20 years. Sex, BMI, AHR, ECP and change in height between 14 and 20 years were identified as independent factors associated with the change in FEV(1) , FVC and FEV(1) /FVC ratio in adolescence. We did not find an association between CRP levels at age 14 and change in lung function by age 20; whereas, sex, change in height, BMI, AHR and ECP were associated with lung function change in adolescence. Our findings indicate that systemic inflammation is of less importance for change in lung function in adolescence. Please cite this paper as: Nybo M, Hansen HS, Siersted HC and Rasmussen F. No relationship between lung function and high-sensitive C-reactive protein in adolescence.

Gender-Related Tumor Necrosis Factor-α Responses in Naïve Volunteers With Toll-Like Receptor 4 Polymorphisms Exposed in a Swine Confinement Facility

The aim of this work is to better understand the responses of people that are exposed to agricultural organic dust and other factors in modern swine production. We investigated the effects of toll-like receptor 4 (TLR4) genotype and gender on respiratory responses of naïve volunteers (18-28 years) to swine barn exposure. Non-smoking healthy subjects (16 men and 13 women) with TLR4 299 (Asp299Gly) and/or 399 (Thr399Ile) polymorphisms (TLR4 299/399) and age-sex matched subjects with TLR4 wild-type alleles spent 5 h in a nonexposed environment (baseline day) and 5 h in a swine facility (exposure day). The results showed significant decreases between baseline and exposure days in across-shift forced vital capacity (FVC), forced expiratory volume in 1 second (FEV(1)), forced midexpiratory flow rate (FEF(25-75)), and FEV(1)/FVC ratio and in methacholine concentration that reduced FEV1 by 20% (PC(20)) in all groups; however, there were no differences by sex or genotype. Similarly, nasal cytokines, serum cytokines, and blood neutrophil count increased after exposure; in contrast, however, these were influenced by gender. The increase in serum tumor necrosis factor-alpha (TNF-alpha) between baseline and exposure was gender-dependent with male sex associated with a significant increase in the wild-type group and female sex associated with a significant increase in the polymorphic group. These results suggest that for persons exposed to a swine facility, one's immunological response varies with gender as well as TLR4 genotype.

Ventilatory function in breath-hold divers: effect of glossopharyngeal insufflation

This study was conducted to determine whether ventilatory parameters would change in breath-hold divers (BHDs) after they performed the glossopharyngeal technique for lung insufflation. Fifteen elite BHDs, 16 non-expert BHDs and 15 control subjects participated in this cross-sectional study. Volumes and expiratory flow rates were measured twice, before and after the glossopharyngeal technique performed at rest. Before the technique, greater forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV(1)) and lower FEV(1)/FVC were noted in the elite and non-expert BHDs compared with controls. No difference was noted regarding the other pulmonary parameters. After the technique, increases were noted in FVC, FEV(1) and maximal voluntary ventilation in the elite BHDs (P < 0.001, respectively). The FEF(25-75%)/FVC ratios were lower in the BHDs both before and after the technique, indicating possible dysanapsis. The ventilatory parameters observed after the glossopharyngeal technique indicated (1) higher lung volumes in expert BHDs and (2) a correlation with BHD performance (maximal dynamic BH performance). This correlation became more significant after the technique, indicating a positive effect of glossopharyngeal insufflation on performance.

HRCT and pulmonary function tests in monitoring of lung involvement in juvenile systemic sclerosis

To investigate the role of high-resolution computed tomography (HRCT) and pulmonary function tests (PFTs) in staging pulmonary involvement in juvenile systemic sclerosis (JSS). Clinical charts of 17 JSS patients (pts) were reviewed and high-resolution CT (HRCT) scans and PFTs performed at first and last visit were examined. Forced expiratory volume in 1 sec (FEV(1)), forced vital capacity (FVC) and carbon monoxide diffusing capacity [DL(CO)] were measured (% pred. values) while HRCT changes were graded according to the Schurawitzki method (min-max score: 0-18). At initial assessment, 10 pts (58.8%) had pulmonary involvement (HRCT score >0 and/or PFTs <80% pred. values). PTFs abnormalities were consistent with a restrictive defect, with low FEV(1), FVC and DL(CO) values and normal FEV(1)/FVC ratio. At first visit HRCT scores were inversely correlated with FEV(1) (r = -0.75; P = 0.02), FVC (r = -0.685; P = 0.035), and DL(CO) values (r = -0.71; P = 0.03), but not with the FEV(1)/FVC ratio (r = -0.36; P = 0.31). Stronger inverse correlations were detected at last visit (median time interval: 4.3 years; min-max: 1-10 years) between HRCT and FEV(1) (r = -0.86; P = 0.002), FVC (r = -0.79; P = 0.009) and DL(CO) (r = -0.79; P = 0.009), but not with the FEV(1)/FVC ratio (r = -0.33; P = 0.35). Changes in HRCT scores between first and last visit were correlated with changes in FEV(1) (r = -0.74; P = 0.02), FVC (r = -0.81; P = 0.007), but not in DL(CO) values (r = 0.07;P = 0.84). At the last visit, of the 10 pts with pulmonary involvement at initial assessment 5 showed worsening of lung involvement and 5 either no significant changes in PFTs and HRCT or mild improvement. PFTs, namely lung volumes, represent a reliable "monitoring" tool in children with JSS to identify pts that need to undergo an HRCT to rule out initial pulmonary involvement and to monitor the course of ILD over time. The weaker clinical value of DL(CO) may relate to poor lung function technique in some younger children.

The Influence of Chronic Heart Failure on Pulmonary Function Tests in Patients Undergoing Orthotopic Heart Transplantation

Chronic heart failure and airway obstruction produce overlapping syndromes. Existent criteria for the diagnosis and grading of airway obstruction based on spirometry results may be inadequate in the presence of coexistent cardiac failure. The cardiac component of pulmonary function tests (PFT) can be measured in patients undergoing orthotopic heart transplantation (OHT). Before and 1 year after OHT between 2006 and 2008 PFT were performed in 29 patients according to existent guideline. Willcoxon matched pair tests were used for analysis in Statistica 7.1. The general group characteristic included age, gender, New York Heart Association class, CCS class, body mass index, present medications, blood and chemistry tests, as well as exercise tolerance tests, right heart catheterization, and echocardiography results. One year after OHT we observed significant improvements in forced expiratory volume in the first second (FEV1) and its percent of normal value (FEV1%) as well as forced vital capacity (FVC), FVC%, vital capacity (VC) and VC%: namely, 2.56 L versus 2.96 L; 82% versus 93%; 3.30 L versus 3.81 L; 85% versus 97%; 3.38 L versus 4.04 L and 85% versus 100% (all P < .01). FEV1 and FVC increments of: 0.39 and 0.471 respectively, exceeded the cutoff point of 12% of predicted value established as the spirometry criterion for reversibility of obstruction. Elimination of heart failure by OHT did not significantly change the FEV1 to FVC ratio (FEV1%FVC). Chronic heart failure contributed to significant FEV1 reduction, which limits the usefulness of PFT for diagnosis and grading of airway obstruction. FEV1%FVC, the main diagnostic criterion of chronic obstructive lung disease, seems to be an index independent of concomittant heart function impairment.

Pulmonary function changes in children after transcatheter closure of atrial septal defect

This study was performed to assess changes in pulmonary function test (PFT) and pulmonary outcome after transcatheter closure of atrial septal defect (ASD) in pediatric patients. A total 55 pediatric patients undergoing transcatheter ASD closure received PFT at baseline (day before ASD closure), and at 3 days and 6 months after procedure. Forced vital capacity (FVC), forced expired volume in 1 sec (FEV(1)), FEV(1) to FVC ratio (FEV(1)/FVC), peak expiratory flow (PEF), and mean forced expiratory flow during the middle half of FVC (FEF(25-75)) were measured. Individually, subjects were classified by spirometry as normal, obstructive or restrictive, to evaluate the effect of transcatheter closure on pulmonary outcome. These 55 children had significantly reduced mean PEF and FEF(25-75) (84 +/- 24%, P = 0.040 and 76 +/- 22%, P = 0.010, respectively) at baseline, with FEF(25-75) reduced significantly at 3 days and 6 months (78 +/- 24%, P = 0.010 and 81 +/- 24%, P = 0.040, respectively) after transcatheter closure. Six months after transcatheter closure of ASD, significant improvement was observed in mean FVC (94 +/- 19% vs. 98 +/- 15%, P = 0.034) and FEV(1) (90 +/- 20% vs. 96 +/- 19%, P = 0.008). Assessed individually, better pulmonary outcome was found in patients without pulmonary hypertension (PH) (chi(2) = 8.333, P = 0.044). PFT disturbance was observed in significant flow limitation in the peripheral airway of ASD patients. Improved PFT was found after transcatheter closure and better pulmonary outcome was observed in patients without PH. ASD children need monitoring pulmonary function and should receive transcatheter closure before PH develops.

What defines airflow obstruction in asthma?

Asthma guidelines from the Global Initiative for Asthma (GINA) and from the National Heart, Lung, and Blood Institute provide conflicting definitions of airflow obstruction, suggesting a fixed forced expiratory volume in 1 s (FEV(1))/forced vital capacity (FVC) cut-off point and the lower limit of normality (LLN), respectively. The LLN was recommended by the recent American Thoracic Society/European Respiratory Society guidelines on lung function testing. The problem in using fixed cut-off points is that they are set regardless of age and sex in an attempt to simplify diagnosis at the expense of misclassification. The sensitivity and specificity of fixed FEV(1)/FVC ratios of 0.70, 0.75 and 0.80 versus the LLN were evaluated in 815 subjects (aged 20-44 yrs) with a diagnosis of asthma within the framework of the European Community Respiratory Health Survey. In males, the 0.70 ratio showed 76.5% sensitivity and 100.0% specificity, the 0.75 ratio 100.0% sensitivity and 92.4% specificity, and the 0.80 ratio 100.0% sensitivity but 58.1% specificity. In females, the 0.70 ratio showed 57.3% sensitivity and 100.0% specificity, the 0.75 ratio 91.5% sensitivity and 95.9% specificity, and the 0.80 ratio 100.0% sensitivity but 72.9% specificity. The fixed cut-off points cause a lot of misidentification of airflow obstruction in young adults, with overestimation with the 0.80 ratio and underestimation with the 0.70 ratio. In conclusion, the GINA guidelines should change their criteria for defining airflow obstruction.

Comparison of the efficacy and safety of arformoterol 15 μg twice daily and arformoterol 30 μg once daily in COPD: A single-dose, multicenter, randomized, modified-blind, two-way crossover study

Objective: The aim of this study was to compare the efficacy and safety of nebulized arformoterol 15 μg/2 mL twice daily (ARF15 BID) and 30 μg/4 mL once daily (ARF30 QD) in subjects with moderate to severe chronic obstructive pulmonary disease (COPD). Methods: In this single-dose, multicenter, randomized, modified-blind, 2-way crossover study, subjects aged ≥45 years with moderate to severe COPD, a forced expiratory volume in 1 second (FEV 1) ≥0.7 L, and ≤65% predicted FEV1, and a FEV 1:forced vital capacity ratio ≤70% were randomly assigned to receive single-day treatment with ARF15 BID or ARF30 QD in random order, separated by a 5 ± 2-day washout period. The primary efficacy end point was time-normalized AUC of FEV 1 from baseline (hour 0) to 24 hours (FEV 1AUC 0–24). Secondary efficacy end points were time-normalized AUC of FEV 1 from baseline to 12 hours (FEV 1AUC 0–12) and from 12 to 24 hours (FEV 1AUC 12–24), and FEV 1 at 24 hours after administration of the morning dose (trough FEV 1). Equivalence of the 2 therapies was assessed by comparing the 90% CI value for the difference of the least squares mean (LSM) to a study-specific predefined equivalence range for change in FEV 1AUC 0–24 of −0.07 to 0.07 L. Results: A total of 33 subjects were enrolled (20 men, 13 women; mean [SD] age, 64.5 [8.8] years; 15 subjects received ARF15 BID first; 18 received ARF30 QD first). ARF15 BID and ARF30 QD were associated with similar improvements from baseline in (FEV 1AUC 0–24, LSM 0.15 and 0.16 L, respectively; Δ, 0.01 L; 90% CI, −0.02 to 0.04) and trough FEV 1 (LSM, 0.15 and 0.12 L, respectively; Δ, −0.03 L; 90% CI, −0.09 to 0.03). FEV 1AUC 0–12 was improved more with ARF30 QD than ARF15 BID (Δ, 0.06 L; 90% CI, 0.04 to 0.09), and FEV 1AUC 12–24 was improved more with ARF15 BID than ARF30 Qd (Δ, −0.04 L; 90% CI, −0.08 to 0.01). The 90% CI for FEV 1AUC 0–24 for the treatment difference between ARF15 BID and ARF30 QD was within the prespecified range of −0.07 to 0.07 L, indicating that both treatments resulted in equivalent FEV 1AUC 0–24 values. Conclusions: In these subjects with moderate to severe COPD, single-day administrations of ARF15 BID or ARF30 QD were associated with FEV 1 responses over a period of 24 hours that were considered equivalent per the protocol definition employed in the present study. FEV1 improvement over 12 hours was greater for ARF30 QD after the morning dose and for ARF15 BID after the evening dose. ClinicalTrials.gov Identifier: NCT00571428

Bronchial nitric oxide is related to symptom relief during fluticasone treatment in COPD

High levels of exhaled nitric oxide (NO) predict favourable response to inhaled corticosteroids in asthma, but the ability of exhaled NO or inflammatory markers in exhaled breath condensate (EBC) to predict steroid responsiveness in chronic obstructive pulmonary disease (COPD) is not known. We measured alveolar and bronchial NO output, levels of leukotriene B(4) (LTB(4)), cysteinyl leukotrienes (cysLTs) and 8-isoprostane in EBC, spirometry, body plethysmography and symptoms in 40 subjects with COPD before and after 4 weeks of treatment with inhaled fluticasone (500 microg b.i.d.). Five subjects (12.5%) with COPD had significant improvement in lung function during fluticasone treatment, whereas 20 subjects (50%) had significant decrease in symptoms. High baseline bronchial NO flux was associated with higher increase in forced expiratory volume in 1 s to forced vital capacity ratio (r = 0.334, p = 0.038) and more symptom relief (r = -0.317, p = 0.049) during the treatment. Baseline EBC levels of LTB(4), cysLTs or 8-isoprostane were not related to response to fluticasone treatment. Inhaled fluticasone decreased bronchial NO flux but not alveolar NO concentration or markers in EBC. High levels of bronchial NO flux are related to symptom relief and improvement of airway obstruction during treatment with inhaled fluticasone in COPD. Markers of inflammation or oxidative stress in EBC are not related to steroid responsiveness in COPD.

Vascular endothelial growth factor levels in induced sputum and emphysematous changes in smoking asthmatic patients

Although asthmatic patients frequently smoke cigarettes, the effect of smoking on asthmatic lungs has not been extensively studied. Vascular endothelial growth factor (VEGF) has been suggested to play a role in the pathogenesis of asthma and emphysema. To determine whether the level of airway VEGF might be related to emphysematous lung changes in asthmatic patients with a history of smoking. Pulmonary function tests and volumetric computed tomography (CT) of the lungs were performed in 10 ex-smoking and 15 nonsmoking asthmatic patients. Levels of VEGF were evaluated in the supernatants of induced sputum using an enzyme-linked immunosorbent assay method in these 25 asthmatic patients and in 10 healthy nonsmoking controls. Associations among sputum VEGF levels, emphysema indices on CT, and clinical variables were analyzed. Ex-smoking asthmatic patients showed a higher emphysema index on volumetric CT and a decreased mean forced expiratory volume in 1 second to forced vital capacity ratio compared with nonsmoking asthmatic patients. Sputum VEGF levels in asthmatic patients with a history of smoking were significantly lower than those in nonsmoking asthmatic patients but remained higher than those in control subjects. Furthermore, the emphysema index was significantly correlated with sputum VEGF levels in asthmatic patients. Lower VEGF levels in the airway might bea surrogate marker for emphysematous changes in the lungs, especially in asthmatic patients with a history of smoking.

25-Year-Old Woman With Increasing Abdominal Girth and Shortness of Breath

25-Year-Old Woman With Increasing Abdominal Girth and Shortness of Breath

Difference of Sentinel Lymph Node Identification Between Tin Colloid and Phytate in Patients With Non–Small Cell Lung Cancer

The advantages and disadvantages of technetium Tc 99m tin colloid and technetium Tc 99m phytate as tracers for sentinel node (SN) identification in patients with clinical stage I non-small cell lung cancer were examined retrospectively. Sentinel node identification was conducted using tin colloid and phytate, respectively, in 73 and 74 patients with clinical stage I non-small cell lung cancer. We compared these two tracers in terms of identification rates, numbers of SNs, characteristics of patients whose SNs could not be identified, and the pathologic results of SNs. The tin colloid tracer identified SNs in 54 of the 73 patients (74%), which was significantly lower than the 89% (66 of 74 patients) in the phytate group (p = 0.02). The number of SNs per patient was 1.7 +/- 0.8 in the tin colloid group, which was significantly less than the 2.4 +/- 1.5 in the phytate group (p = 0.002). Although patients in the tin colloid group whose SNs could not be identified had a significantly lower forced expiratory volume in 1 second to forced vital capacity ratio than those whose SNs could be identified (p = 0.04), the phytate group did not show such a difference. Eleven of 120 patients whose SNs could be identified had pathologic N1 or N2 disease, but neither group showed any false-negative results for SN identification. Both tin colloid and phytate are reliable tracers for identifying SNs in non-small cell lung cancer. The advantage of phytate is that SNs can be detected more frequently than with tin colloid, even in patients with a low forced expiratory volume in 1 second to forced vital capacity ratio. However, tin colloid requires fewer nodes than phytate to identify SNs.

Quality of life measured by the St George's Respiratory Questionnaire and spirometry

The present authors aimed to determine if the criteria for the diagnosis of chronic obstructive pulmonary disease (COPD) and its classification by severity as recommended by the Global Initiative for Chronic Obstructive Lung Disease are supported by measurements of respiratory health-related quality of life. A community-based sample of adults aged 25-75 yrs had pre- and post-bronchodilator spirometry and completed the St George's Respiratory Questionnaire (SGRQ). Loess scatter plot smoothers of the SGRQ versus post-bronchodilator forced expiratory volume in one second (FEV(1))/forced vital capacity (FVC) ratio and post-bronchodilator FEV(1) % predicted together with receiver operating characteristic (ROC) curve analysis were used to determine the relationship between spirometric variables and clinically important differences in the SGRQ score. The scatter plot smoother and ROC curve analyses supported the value of 0.7 for post-bronchodilator FEV(1)/FVC ratio, which was approximately 4 units higher than the nadir of the SGRQ. To represent a distance of 8 units on the SGRQ, the cut-off points for post-bronchodilator FEV(1) that delimit COPD severity stages were 80, 60 and 40% pred for mild, moderate and severe COPD, respectively. To diagnose chronic obstructive pulmonary disease the use of post-bronchodilator forced expiratory volume in one second/forced vital capacity ratio of 0.7 is supported by health-related quality of life measurements. There may be advantages in using forced expiratory volume in one second cut-off points of 80, 60 and 40% predicted for the classification of mild, moderate and severe chronic obstructive pulmonary disease, respectively, similar to the approach recommended for asthma.

Intermittent Wound Perfusion for Postoperative Pain Relief Following Upper Abdominal Surgery: A Surgeon's Perspective

Although there are many methods for postoperative pain management, implementation may be limited in some settings due to practical or financial constraints. Simple, inexpensive and easily implemented analgesic methods may improve access to effective pain relief. Fifty patients undergoing truncal vagotomy and gastrojejunostomy for pyloric stenosis secondary to chronic duodenal ulceration were studied in this prospective randomized trial. Subjects were assigned to receive either wound perfusion with 8 mL of 0.25% bupivacaine every 5 hours through a catheter placed subcutaneously or intravenous pethidine 0.2 mg/kg on demand for postoperative pain relief. Postoperative pain scores at rest were measured by visual analog scale and the opioid requirement at 0-12 hours, at 12-24 hours and at 24-36 hours were compared. Changes in respiratory parameters were also compared between the two groups. Pain scores at 0-12 hours were significantly lower in the wound perfusion group compared with the intravenous pethidine group (5.7 +/- 1.3 vs. 4.3 +/- 1.2, mean +/- SD; P < 0.001). The number of doses of analgesic required in the wound perfusion group was significantly lower compared with the controls during the 36 hours of study (3.5 +/- 1.3 vs. 1.4 +/- 1.0, P < 0.001). There were no differences in respiratory parameters, vital capacity, forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), and peak expiratory flow rate between the two groups. The FEV1:FVC ratio, however, was significantly higher in the intravenous pethidine group. There were no wound complications due to catheter placement or systemic toxicity due to the anesthetic. Intermittent wound perfusion with 0.25% bupivacaine is a safe and efficient method to reduce pain scores and opioid requirement in the early postoperative period. Wound perfusion, however, had no beneficial effect on the postoperative respiratory function.

Impulse oscillometry versus spirometry in a long-term study of controller therapy for pediatric asthma

Determination of the benefits and limitations of specific physiologic tests has not been well studied in long-term clinical pediatric trials. We sought to determine the utility of impulse oscillometry in a long-term comparison of 3 controller regimens in children with persistent asthma. Children 6 to 14 years of age with mild-to-moderate persistent asthma were characterized with oscillometry and spirometry before entry into a clinical trial and then serially during 48 weeks of therapy with either an inhaled corticosteroid, a combination inhaled corticosteroid with a long-acting beta-agonist, or a leukotriene receptor antagonist. The FEV(1)/forced vital capacity ratio, as well as the forced expiratory flow from 25% to 75% of forced vital capacity in terms of spirometric parameters and the reactance area (XA) from impulse oscillometry, appeared to complement information provided by FEV(1) when comparing the tests and factors that appeared to predict a response to treatment. XA was unique in that it, as distinct from spirometric variables, reflected ongoing improvement during the latter part of the trial. In general, improvements in XA during the latter part of the study occurred independently of indices of atopy and the level of airway responsiveness. Assessment of respiratory mechanics over time with oscillometry might offer additional insights into the response of asthmatic patients to therapy. In particular, the pattern of improvement seen in XA over the course of therapy suggests this test might detect alterations in airway mechanics not reflected by spirometry. The possibility that changes in XA reflect ongoing improvement in small airway function deserves additional study.

Lung function changes following methacholine inhalation in COPD

The non-specific bronchial hyper-responsiveness reported in mild to moderate COPD is usually attributed to reduced airway calibre accentuating the effect of airway smooth muscle shortening. We hypothesized that in more severe COPD the fall in forced expiratory volume in 1 second (FEV(1)) seen during methacholine challenge would result from an increase in residual volume and decrease in vital capacity rather than an increase in airways resistance. Twenty-five subjects with moderate to severe COPD and 10 asthmatic subjects had spirometry and oscillatory mechanics measured before methacholine challenge and at a 20% fall from baseline post challenge (PC(20)FEV(1)). In the COPD subjects median PC(20) was 0.35mg/mL. Comparing baseline to PC(20) there were significant falls in forced vital capacity (FVC) (2.91 vs. 2.2L; p<0.001), slow vital capacity (3.22 vs. 2.58L; p<0.001) and IC (2.21 vs. 1.75L; p<0.001) without change in FEV(1)/FVC ratio (0.52 vs. 0.52; not significant) or in total lung capacity where this was measured. Total respiratory system resistance (R(5)) was unchanged (0.66 vs. 0.68; not significant) but total respiratory system reactance decreased significantly (-0.33 vs. -0.44; p<0.001). In contrast, the asthmatics became more obstructed and showed a proportionally smaller fall in lung volume with increase in R(5) (0.43 vs. 0.64; p<0.01). In moderate to severe COPD the fall in FEV(1) with methacholine is mainly due to increases in residual volume, which may represent airway closure and new-onset expiratory flow limitation.

Effect of Breastfeeding on Lung Function in Childhood and Modulation by Maternal Asthma and Atopy

Guilbert TW, Stern DA, Morgan WJ, Martinez FD, Wright AL. Am J Respir Crit Care Med. 2007;176(9):843–848 PURPOSE OF THE STUDY. Breastfeeding and its relationship to the development of subsequent asthma remain controversial. To clarify these complex issues, this study examined the association between lung function and infant-feeding practices. STUDY POPULATION. A population-based cohort of healthy infants was enrolled at birth in the Children's Respiratory Study in Tucson, Arizona (n = 1246); the analysis was of 679 study participants on whom lung-function testing was performed at ages 11 and/or 16 years and provided data regarding infant-feeding practices. METHODS. In the Children's Respiratory Study in Tucson, feeding practices were assessed prospectively on the basis of questionnaires completed at enrollment and well-child visits. Formula introduction was categorized as having occurred before 2 months (n = 143, “early formula introduction”), from 2 to before 4 months (n = 336), or at ≥4 months (n = 200, “longer breastfed”). Lung function was measured at ages 11 and 16 years. A random-effects model was used to assess the relationship of infant-feeding practices to measures of lung function. RESULTS. Forced vital capacity (FVC) by age 16 was increased by 103 ± 40 mL (P = .01), and the forced expiratory volume in 1 second (FEV1)/FVC ratio was lower (−1.9 ± 0.6%; P = .004) in the longer-breastfed children compared with children with early formula introduction. This effect was modified after stratifying according to maternal asthma. Compared with children with early formula introduction, longer-breastfed children with asthmatic mothers had an FVC that was not increased (P = .7) and an FEV1/FVC ratio (−5.7 ± 2.4%; P = .02) that was significantly decreased by age 16. Longer-breastfed children with nonatopic, nonasthmatic mothers demonstrated an increased FVC (142 ± 71 mL; P = .047) and no decrease in FEV1/FVC (P = .7) compared with children with early formula introduction. CONCLUSIONS. Longer duration of breastfeeding favorably influences lung growth in children. However, in the presence of maternal asthma, longer breastfeeding is associated with decreased airflows. REVIEWER COMMENTS. There seems to be a differential effect of the relation of breastfeeding to lung function on the basis of the asthmatic background of the mother. Breastfed children with nonatopic, nonasthmatic mothers had an increased FVC and no decrease in their airflows. However, children of mothers with asthma with longer breastfeeding did not demonstrate any improvement in FVC but had a significant reduction in airflows, suggesting that the risk for increased asthma in this group may be partly a result of altered lung growth. Children with longer breastfeeding who had atopic but nonasthmatic mothers had intermediate findings, and they showed a similar increase in FVC compared with those with nonatopic, nonasthmatic mothers but a decrease in airflows similar to children with asthmatic mothers. These findings may support the speculation that the milk of mothers with atopy or asthma may differ with regard to immunologically active substances; thus, breastfeeding in these groups may have a different effect on growth and/or development of the airways. It goes without saying that the clinical significance of these findings is unknown. Human milk is uniquely suited to the feeding of infants. There are many well-documented benefits of breastfeeding. For children of nonasthmatic mothers, this study demonstrates a further benefit of breastfeeding. Additional study is needed draw firm conclusions for other infants.

Induced Sputum in Systemic Sclerosis Interstitial Lung Disease: Comparison to Healthy Controls and Bronchoalveolar Lavage

Background: Induced sputum (IS) is a noninvasive tool, which can be used to collect cellular and soluble materials from lung airways. Objective: To evaluate if IS may be a useful and safe tool for the detection of airway inflammation in patients with interstitial lung disease (ILD) in systemic sclerosis (SSc). Methods: Sixty-eight patients with SSc and ILD as well as 18 healthy individuals (controls) were selected and submitted to IS examination. In 34 of 68 patients with SSc, bronchoalveolar lavage (BAL) was also performed. Safety of IS was assessed by comparison of forced expiratory volume in the first second (FEV₁), FEV₁/forced vital capacity ratio and peak expiratory flow before and after the IS procedure. Cell composition in samples collected by BAL and IS was correlated, and IS total and differential cell count in SSc patients and controls were compared. Results: The total number of cells was significantly higher in IS samples of SSc patients compared to those of healthy controls. Mean percentage of neutrophils was also higher in SSc patients (41.79 ± 23.89 vs. 27.37 ± 17.90), as well as lymphocytes (17.42 ± 19.70 vs. 3.13 ± 2.28) and eosinophils (2.35 ± 4.43 vs. 0.41 ± 0.46). On the other hand, mean percentage of macrophages was higher in healthy individuals (69.10 ± 19.15 vs. 36.96 ± 20.68). In fluid recovered by BAL, the most frequent cells were macrophages (67.89% ± 17.26), while neutrophils (14.77 ± 17.18%) and lymphocytes (15.62 ± 13.46%) were less frequent and eosinophils (1.66 ± 2.08%) were rare. A similar pattern of cell composition was found in IS samples (41.15 ± 21.67% of macrophages, 39.72 ± 23.15% of neutrophils, 15.28 ± 19.46% of lymphocytes and 2.56 ± 5.03% of eosinophils). Strength of correlation between BAL and IS was significant for macrophages and neutrophils. After IS procedure was performed, improvement of FEV₁ (mean value before IS was 85.09 ± 14.44 and 88.93 ± 16.40 after IS) and FEV₁/forced vital capacity (mean value before IS was 98.53 ± 12.11 and 105.22 ± 10.78 after IS) was observed. Conclusion: The IS method may allow a noninvasive assessment of cell composition in airway fluid and may contribute to the better understanding of upper/medium airway inflammation in SSc. Future studies are needed to verify whether IS can replace invasive procedures for the detection and monitoring of lung inflammation in SSc.

Genetic variation of IL13 as a risk factor of reduced lung function in children and adolescents: A cross-sectional population-based study in Korea

Previous investigations have suggested that genetic variations are associated with reduced lung function in early childhood. This study was conducted to evaluate the association between IL13+2044G-->A, the functionally relevant single nucleotide polymorphism (SNP) in the gene coding IL13, and lung function in early childhood. A total of 1900 subjects aged 10-18 years living in Korea, were randomly recruited. Lung function test and methacholine bronchial provocation test were performed. Multiple regression analysis adjusting for sex, age, height, atopy, and history of passive smoking was done to evaluate effect of IL13+2044G-->A on lung function. Mean (+/-SD) forced expiratory volume in 1 s (FEV(1)) was 2.66 L (+/-0.60) in subjects with the AA or AG genotype (n=982) and 2.75 L (+/-0.57) in subjects with the GG genotype (n=918). IL13+2044G-->A showed a significant association with FEV(1) [in the minor allele dominant model (GG vs. AG+AA), P<0.001]. Interestingly, the association between FEV(1) and IL13+2044G-->A remained still significant in subgroup analysis according to the presence of AHR (P<0.001 in subjects without AHR and P=0.002 in subjects with AHR). Moreover, FEV(1)/FVC (forced vital capacity) ratio also showed a significant association with IL13+2044G-->A in both groups (P<0.001 in subjects without AHR and P<0.001 in subjects with AHR). This cross-sectional study demonstrates that IL13+2044G-->A is significantly associated with a reduced lung function in Korean children and adolescents.

Improvement of restrictive and obstructive pulmonary mechanics following laparoscopic bariatric surgery

Morbidly obese patients often have impaired respiratory mechanics leading to restrictive and obstructive lung diseases. Weight loss after bariatric surgery has been shown to improve or resolve many obesity-related comorbidities. However, few studies have examined long-term changes in pulmonary mechanics after bariatric surgery. We hypothesize that pulmonary function improves after surgically induced weight loss. We examined the pulmonary function of 104 morbidly obese patients who underwent laparoscopic gastric bypass or gastric banding. Pulmonary studies, including forced expiratory volume in 1 s (FEV(1)), forced vital capacity (FVC), peak expiratory flow (PEF), and forced expiratory volume at midexpiratory phase (FEV(25-75%)) were measured preoperatively and at 3-month intervals. All results are expressed as a percentage of the baseline values. There were 80 females and 24 males with a mean age of 41 years. The mean body mass index was 48 kg/m(2). The mean percentage of excess body weight loss at 12 months was 54%. At 12 months postoperatively, restrictive pulmonary mechanics significantly improved as demonstrated by an increase in the FEV(1) to 112% of baseline value, increase in the FVC to 109% of baseline value, increase in the PEF to 115% of baseline value, and increase in the FEV(25-75%) to 130% of baseline value. Additionally, the percentage of patients with obstructive lung pattern (FEV(1)/FVC ratio less than 0.8) decreased from 9.6% preoperatively to 1.9% postoperatively (p=0.03). Weight loss after laparoscopic gastric bypass significantly improves restrictive and obstructive respiratory mechanics. The improvements were observed as early as 3 months postoperatively.