Body mass index correlated with forced expiratory volume in 1 second/forced vital capacity in a population with a relatively low prevalence of obesity

Background Obesity is the most common metabolic disease in the world. However, the relationship between obesity and lung function is not fully understood. Although several longitudinal studies have shown that increases in body weight can lead to reductions in pulmonary function, whether this is the case with the Japanese population and whether high body mass index （BMI） status alone represents an appropriate predictor of obstructive lung dysfunction remains unclear.The purpose of present study was to estimate the effect of BMI on lung function measured by spirometry of Japanese patients in general clinics. We measured BMI and performed spirometry on screening patients who had consulted general clinics.Methods Subjects comprised 1231 patients ≥40 years of age （mean age （65.0±12.0） years, 525 men, 706 women） who had consulted clinics in Nagasaki Prefecture, Japan, for non-respiratory disease. BMI was calculated and lung function was measured by spirometry.Results BMI was found to be positively correlated with forced expiratory volume in 1 second （FEV1）/forced vital capacity （FVC） in men and with maximum mid-expiratory flow （MMF） in all subjects. Following adjustment for relevant factors, a significant positive correlation between BMI and FEV1/FVC was identified for all subjects. Comparison between subjects with normal BMI （18.5-25.0） and higher BMI （25.1-30.0） also demonstrated that FEV1/FVC and percentage of predicted maximum mid-expiratory flow （%MMF） were significantly higher in the latter subjects.Conclusions In a population without marked respiratory disease, higher BMI subjects showed less obstructive pulmonary dysfunction compared to normal BMI subjects. High BMI status alone may be inappropriate as a predictor of obstructive lung dysfunction, particularly in populations with a low prevalence of obesity.

Expiratory Flow Limitation and Its Relation to Dyspnea and Lung Hyperinflation in Patients with Chronic Obstructive Pulmonary Disease: Analysis Using the Forced Expiratory Flow-Volume Curve and Critique

Background: Tidal expiratory flow limitation (tEFL) is defined as absence of increase in air flow during forced expiration compared to tidal breathing and is related to dyspnea at rest and minimal exertion in patients with chronic airflow limitation (CAL). Tidal EFL has not been expressed as a continuous variable (0% - 100%) in previous analyses. Objective: To relate the magnitude of tEFL to spirometric values and Modified Medical Research Council (MMRC) score and Asthma Control Test (ACT). Methods: Tidal EFL was computed as percent of the tidal volume (0% - 100%) spanned (intersected) by the forced expiratory-volume curve. Results: Of 353 patients screened, 192 (114 M, 78 F) patients (136 with COPD, 56 with asthma) had CAL. Overall characteristics: (mean ± SD) age 59 ± 11 years, BMI 28 ± 7, FVC (% pred) 85 ± 20, FEV1 (% pred) 66 ± 21, FEV1/FVC 55% ± 10%, RV (% pred) 147 ± 42. Tidal EFL in patients with tEFL was 53% ± 39%. Using univariate analysis, strongest correlations were between tEFL and FVC and between tEFL and RV in patients with BMI < 30 kg/m2. In patients with nonreversible CAL, tEFL was positively associated with increasing MMRC, negatively with spirometric measurements, and positively with RV/TLC. In asthmatics, ACT scores were higher in patients with mean BMI ≥ 28 kg/m2 (p < 0.00014) and RV/TLC values > 40% (p < 0.03). Conclusions: Dyspnea is strongly associated with tEFL and lung function, particularly in patients with nonreversible CAL. Air trapping and BMI contribute to tEFL.

Role of peripheral eosinophilia in acute exacerbation of chronic obstructive pulmonary disease

BACKGROUND Eosinophil counts are a promising guide to systemic steroid administration for chronic obstructive pulmonary disease(COPD).AIM To study the role of peripheral eosinophilia in hospitalized patients with acute exacerbation of COPD(AECOPD).METHODS From January 2014 to May 2017,patients with AECOPD hospitalized in Taipei Tzu Chi Hospital were retrospectively stratified into two groups according to their peripheral eosinophil count:The EOS group(eosinophil count≥2%)and the non-EOS group(eosinophil count<2%).Demographics,comorbidities,laboratory data,steroid use,length of hospital stay,and COPD-related readmissions were compared between the groups.RESULTS A total of 625 patients were recruited,with 176 patients(28.2%)in the EOS group.The EOS group showed a lower prevalence of infection,lower cumulative doses of prednisolone equivalents,shorter length of hospital stay,and higher number of COPD-related readmissions than the non-EOS group.There were significantly linear correlations between eosinophil percentage and number of readmissions and between eosinophil percentage and length of hospital stay P<0.001,and a lower percent-predicted value of forced expiratory volume in one second(FEV1)were associated with shorter time to first COPD-related readmission[adjusted hazard ratio(adj.HR)=1.488,P<0.001;adj.HR=0.985,P<0.001,respectively].CONCLUSION The study findings suggest that the EOS group had the features of a shorter length of hospital stay,and lower doses of systemic steroids,but more frequent readmissions.The EOS group and lower percent-predicted FEV1 values were risk factors for shorter time to first COPD-related readmission.

Exercise-Induced Bronchoconstriction Diagnostics:Impact of a Repeated Exercise Challenge Test

Exercise-Induced bronchoconstriction (EIB) is related to increased ventilation (VE) during exercise and describes the transient airway narrowing following exercise. A reliable diagnosis is essential for optimal treatment. The impact of a repeated exercise challenge test (ECT) in a clinical setting is not well established and conducting a repeated ECT with the possibility to adjust the exercise intensity on an individual basis may give more information. The aim of the study was to evaluate the test-retest reliability of an ECT for EIB and its association with exercise intensity. Methods: After examination by a pulmonologist, 20 referred subjects with symptoms strong indications of Exercise-Induced bronchoconstriction performed two consecutive exercise challenge tests on a treadmill. The exercise intensity of the repeated test was adjusted. Forced expiratory volume in 1 second (FEV1) was measured before and 1, 3, 6, 10, and 15 minutes after exercise. EIB was defined as a reduction of ≥ 10% in FEV1. Ventilation and heart rate were measured during exercise. Results: Five subjects tested positive in both tests, and ten subjects tested negative in both tests. Three subjects tested positive in the first test only, while two subjects tested positive in the second test only. The exercise intensity was not significantly different between the two tests for any of the subjects. Conclusion: There were 25% divergences in the diagnostic results of two consecutive exercise challenge tests. The difference in the test results was not explained by a difference in the exercise intensity.

Correlation of eosinophil counts in induced sputum and fractional concentration of exhaled nitric oxide and lung functions in patients with mild to moderate asthma

Background The airway inflammation could be assessed by some noninvasive approaches. To investigate the value of eosinophil counts in induced sputum and fractional concentration of exhaled nitric oxide （FENO） for the regimen adjustment in patients with asthma, the correlation was analyzed between the two parameters and lung function parameter （forced expiratory volume in one second （FEV1））. Methods Sixty-five outpatients with mild to moderate non-exacerbation asthma from Beijing Chao-Yang Hospital were enrolled as treatment group. Combined medications of inhaled corticosteroids plus long-acting beta-2 agonist were administered for one year. Lung function parameters, eosinophil counts in induced sputum, concentration of exhaled nitric oxide and the Asthma Control Test scores were recorded, at regular intervals in the follow-up period. Twenty-one healthy volunteers were enrolled as control group and underwent examination of eosinophil counts in induced sputum, lung function and concentration of exhaled nitric oxide. Results Sixty-three subjects from treatment group completed follow-up period for one year or longer. Mean FEV1 value of the 63 subjects was （2.75±0.54） L at baseline, （2.97±0.56） L and （3.07±0.52） L at month 3 and month 6, respectively, and maintained as （3.14±0.51） L in the following six months. Mean FENO decreased from （61±25） parts per billion （ppb） at baseline to （32±19） ppb at month 3 （P 〈0.05）, and continued to decrease to （22±12） ppb at month 6, the difference being significant when compared to both baseline and control group （（13±8） ppb）. Mean eosinophil counts decreased to （0.032±0.011） ×106/ml at month 3, which was significantly different from baseline （（0.093±_0.023） xl06/ml） and the control group （（0.005±0.003）×l06/ml （both P 〈0.05）. The eosinophil counts in induced sputum correlated positively with concentration of FENO in the first six months （all P 〈0.05）. The concentration of FENO had a significant negative correlation with FEV1 value （all P 〈0.05） in any time point in the follow-up period. The Asthma Control Test scores were 18±5, 19±7, 23±-2, 24±1 and 24±1 at months 1, 3, 6, 9 and 12, respectively, which were significantly different from the score at baseline （14±3） （P 〈0.05 ）. The most rapid clinical effect was observed at the second month after treatment. Conclusion Eosinophil counts in induced sputum and FENO are sensitive parameters to detect airway inflammation and may be useful in evaluating the efficacy of treatment and adjusting medication regimens.

Age-associated changes in pulmonary function： a comparison of pulmonary function parameters in healthy young adults and the elderly living in Shanghai

Background The respiratory system changes with age and a better understanding of the changes contribute to detect and prevent respiratory dysfunctions in old population. The purpose of this study was to observe age-associated changes of pulmonary function parameters in healthy young adults and the elderly. Methods A cross-sectional study was conducted among 600 male and female subjects aged 19 to 92 years. The subjects were divided into three groups by age： young adult （19-39 years）, middle-aged adult （40-59 years）, and the elderly （〉60 years）. The pulmonary function was measured with routine examination methods and 13 parameters including vital capacity （VC）, residual volume （RV）, functional residual capacity （FRC）, total lung capacity （TLC）, RV/TLC, forced vital capacity （FVC）, forced expiratory volume in one second （FEV1）, FEV1/FVC, peak expiratory flow （PEF）, forced expiratory flow at 25% of FVC exhaled （FEF25）, forced expiratory flow at 50% of FVC exhaled （FEF50）, diffusion capacity of the lung for carbon monoxide （DLCO）, and specific diffusion capacity of CO （KCO） were collected and analyzed. Changes in pulmonary function parameters among the influence on FEVJFVC and RV were studied further. Results Ten pulmonary function parameters including VC, FVC, pre-elderly and elderly subjects, especially the aging FEV1, FEV1/FVC, PEF, FEF25, FEF50, TLC, DLCO and KCO decreased significantly with age in both male and female subjects （P 〈0.01）. RV and RV/TLC were increased with age （P 〈0.01）. FRC remained stable during aging. Except FRC, the linear relationship was significant between age and other pulmonary function parameters. In the pre-elderly and elderly subjects, RV had a non-significantly increasing tendency with age （P 〉0.05）, and FEV1/FVC did not change significantly with age （P 〉0.05）. Conclusion Total pulmonary function was declined tendency of RV and decreasing tendency of FEV1/FVC with advancing age, but FRC was stable, and the increasing obviously slowed down in the pre-elderly and elderly subjects.

Fetal stem cells are effective in the treatment of Grade Ⅰ and Ⅱrespiratory failure in amyotrophic lateral sclerosis and muscular dystrophy

Objectives: To study the effect of fetal stem cell(FSC) therapy on Grade Ⅰ and Ⅱrespiratory failure in patients with amyotrophic lateral sclerosis(ALS) and muscular dystrophy(MD). Methods: A comparative study was conducted on 41 patients with Grade Ⅰ or Ⅱrespiratory failure(RF) resulting from ALS or MD. The patients were divided into 4 groups according to the underlying disease and the degree of RF. Patients underwent combined treatment, including the experimental application of FSC therapy, and were examined before FSC treatment, and 6 months and 12 months after treatment. Results: FSC treatment improved both subjective and objective breathing parameters as early as 6 months post‐treatment. A significant increase in the forced vital capacity(FVC) and forced expiratory volume in 1 second(FEV1) was reported by all patients with grade Ⅰ RF linked to ALS and MD compared to baseline. Patient respiratory improvement was maintained over the next 6 months. Grade Ⅱ RF patients with MD reported a significant improvement in FVC 12 months after treatment. Conclusions: Evidence for respiratory improvement was observed as early as 6 months in all patients after combined treatment including FSC therapy, and this was maintained for a further 6 months after therapy. In MD patients with Grade Ⅱ RF, treatment resulted in a significant FVC and FEV1 increase within 6 months and downgrading to Grade Ⅰ RF within a year after FSC treatment.