• Tuberculosis and Respiratory Diseases
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• v.54 no.2
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• pp.210-218
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• 2003

Background : Sex specific cross sectional reference values for the lung function indices usually employ a linear model with a term for age and height. The purpose of this study was to determine the effects of the body mass index (BMI), the fat percentage of the body mass and the fat-free mass index (FFMI) on the forced expiratory volume curve. Methods : Between January 2000 and December 2001, a total of 300 subjects, 150 men and 150 women (mean age : $45{\pm}13$ years), with a normal lung function were enrolled in the study sample. This study measured the $FEV_1$, FVC and $FEF_{25-75%}$ from the forced expiratory volume curve by a spirometer and the body composition by a bioelectrical impedance method in all subjects. Multiple regression analysis was used in order to examine the effects of the body composition on the parameters derived from the forced expiratory volume curve. Results : After adjusting for age, the BMI and Fat percentage improved the descriptions of the FVC (p<0.05, $r^2=0.491$) and $FEV_1$ (p<0.05, $r^2=0.654$) in women. In contrast, the FFMI contributed significantly to the FVC (p<0.05, $r^2=0.432$) and $FEV_1$ (p<0.05, $r^2=0.567$) in men. The $FEF_{25-75%}$ correlated with the fat percentage in women (p<0.05, $r^2=0.337$). Conclusion : These results suggest that the BMI, the fat percentage and the FFMI are significant determinants of the forced expiratory volume curve. The plmonary function test, when considering the BMI, the fat percentage and the FFMI, might be useful in clinical applications.

• Tuberculosis and Respiratory Diseases
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• v.71 no.6
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• pp.431-437
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• 2011

Background: We tried to examine the small airway diseases which can be found early, in workers exposed to inorganic dusts. This is measured in normal breath by using the impulse oscillometry (IOS). Methods: The Pulmonary function test (forced vital capacit [FVC], forced expiratory volume in one second [$FEV_1$], forced expiratory flow between 25% and 75% of vital capacity [$FEF_{25-75}$]), IOS resistance (Rrs at 5, 10, 15, 20, 25, 35 Hz) and reactance (Xrs at 5, 10, 15, 20, 25, 35 Hz) were measured for 454 workers. The subjects were classified into 173 workers of normal (38.1%) and 281 patients with pneumoconiosis (61.9%). Results: There were significant differences between normal and patients with FVC ($3.82{\pm}0.61$ vs. $3.53{\pm}0.56L$), $FEV_1$ ($2.67{\pm}0.63$ vs. $2.35{\pm}0.48L$), and $FEF_{25-75}$ ($1.88{\pm}0.95$ vs. $1.47{\pm}0.80L/sec$) between groups (p<0.05). And as for IOS, there was no significant difference in resistance (Rrs) (p>0.05), and there were significant differences between normal and patients with reactance (Xrs) 15 Hz ($0.003{\pm}0.05$ vs. $-0.006{\pm}0.04kPa/L/s$), 20 Hz ($0.043{\pm}0.05$ vs. $0.031{\pm}0.04kPa/L/s$), and 35 Hz ($0.141{\pm}0.05$ vs. $0.131{\pm}0.05kPa/L/s$) between groups (p<0.05). Conclusion: We could find out that 15 Hz, 20 Hz, and 35 Hz values of reactance were significantly influenced by pneumoconiosis. When usefulness and reproducibility to carry out the IOS are considered, it is thought that in future work will be required to draw the reference values for normal Korean persons.

• Tuberculosis and Respiratory Diseases
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• v.72 no.3
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• pp.310-317
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• 2012

Background: Airway obstruction and the extent of emphysema are reported to be responsible for reduced bone mineral density (BMD). Corresponding to different phenotypes of a pulmonary disease, different severity in extra pulmonary features may exist. We compared BMDs of subjects with or without airway obstruction and/or emphysema and investigated the relationships among BMD, the severity of airway obstruction, and the extent of emphysema. Methods: Using a university hospital database, we reviewed patients over 40 years old who performed spirometry, computed tomography of chest, and measurement of BMD of the lumbar (L) spine. According to the presence or absence of airway obstruction and/or emphysema, four groups were classified. Results: Among a total of 59 subjects, 33 (56%) had osteoporosis. The prevalence of osteoporosis in subjects with no airway obstruction and no emphysema, those with only emphysema, those with only airway obstruction, and those with both airway obstruction and emphysema were 42%, 57%, 64%, and 73%, respectively (p=0.047 by linear-by-linear association). The mean T-scores of BMD of L1 (p=0.032) and L1-4 spines were different among the four groups (p=0.034). Although the T-score of L1 BMD negatively correlated with the extent of emphysema (r=-0.275, p=0.035) and positively with each of body mass index (BMI) (r=0.520, p<0.001), forced expiratory volume in one second ($FEV_1$) (r=0.330, p=0.011), $FEV_1$/forced vital capacity (r=0.409, p=0.001), and forced expiratory flow at 25~75% of FVC ($FEF_{25-75%}$) (r=0.438, p=0.0001), respectively, multiple linear regression analysis indicated that BMI (p<0.001) and $FEF_{25-75%}$ were predictive of BMD (p=0.012). Conclusion: Low BMI and airway obstruction were strongly associated with reduced bone density rather than the extent of emphysema.

• Tuberculosis and Respiratory Diseases
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• v.69 no.3
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• pp.177-183
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• 2010

Background: Smoking reduces pulmonary function and induces various lung diseases. Recently, the rate of emphysema detection has increased due to lung cancer screening with low-dose chest computed tomography (CT). The purpose of this study was to evaluate changes in lung function associated with emphysema in healthy smokers. Methods: One hundred and ninety one healthy smokers, who had undergone a low-dose chest CT (LDCT) scan as part of lung cancer screening and had revisited the health center after a median 23.9 months' time, were recruited into this study. The severity of emphysema was calculated by the direct observation of a radiologist and a pulmonologist indipendently. Longitudinal changes in lung function according to emphysema based on LDCT and type of smoker was analyzed. Results: Of the participants in this study, 25% of healthy smokers had emphysema, which was mild in severity, in older patients (p=0.003) and in heavy smokers (p<0.001). $FEV_1/FVC$ and FEF25-75% were decreased in current smokers with emphysema (p=0.001 and p=0.009, respectively) and without emphysema (p=0.001 and p=0.042). Although lung function was not decreased in ex-smokers without emphysema, $FEV_1/FVC$ and FEF25-75% were decreased in ex-smoker with emphysema (p=0.020 and p=0.010). Conclusion: Upon examination with LDCT, the prevalence of emphysema was higher in healthy smokers was than in non-smokers. Lung function was diminished in smokers with emphysema, in spite of former smoker.

• Tuberculosis and Respiratory Diseases
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• v.72 no.5
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• pp.433-440
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• 2012

Background: The pulmonary function test is the most basic test method to diagnosis lung disease. The purpose of this study was to research the correlation of the body mass index (BMI), the fat percentage of the body mass (fat%), the muscle mass, the fat-free mass (FFM) and the fat-free mass index (FFMI), waist-hip ratio (WHR), on the forced expiratory volume curve. Methods: Between March and April 2009, a total of 291 subjects were enrolled. There were 152 men and 139 female (mean age, $46.3{\pm}9.92$ years), and they were measured for the following: forced vital capacity (FVC), forced expiratory volume at 1 second ($FEV_1$), and forced expiratory flow during the middle half of the FVC ($FEF_{25-75}$) from the forced expiratory volume curve by the spirometry, and the body composition by the bioelectrical impedance method. Correlation and a multiple linear regression, between the body composition and pulmonary function, were used. Results: BMI and fat% had no correlation with FVC, $FEV_1$ in male, but FFMI showed a positive correlation. In contrast, BMI and fat% had correlation with FVC, $FEV_1$ in female, but FFMI showed no correlation. Both male and female, FVC and $FEV_1$ had a negative correlation with WHR (male, FVC r=-0.327, $FEV_1$ r=-0.36; p<0.05; female, FVC r=-0.175, $FEV_1$ r=-0.213; p<0.05). In a multiple linear regression of considering the body composition of the total group, FVC explained FFM, BMI, and FFMI in order ($r^2$=0.579, 0.657, 0.663). $FEV_1$ was explained only fat% ($r^2$=0.011), and $FEF_{25-75}$ was explained muscle mass, FFMI, FFM ($r^2$=0.126, 0.138, 0.148). Conclusion: The BMI, fat%, muscle mass, FFM, FFMI, WHR have significant association with pulmonary function but $r^2$ (adjusted coefficient of determination) were not high enough for explaining lung function.

• Tuberculosis and Respiratory Diseases
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• v.42 no.4
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• pp.548-554
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• 1995

Background: Cardiogenic pulmonary edema increases nonspecific airway responsiveness in humans and animals. Increased extravascular lung water from overt pulmonary edema to subclinical interstitial edema is a common finding in patients with chronic renal failure. Several studies carried out to assess pulmonary function disturbances in this condition have documented a reduction in forced expiratory volume that usually reverses after hemodialysis, suggesting airway edema as the underlying mechanism. This interstitial edema may also lead to nonspecific bronchial hyperresponsiveness. We hypothesized that patients with chronic renal failure may present nonspecific bronchial hyperresponsiveness due to subclinical interstitial pulmonary edema. Methods: We studied 18 chronic renal failure undergoing regular hemodialysis 3 times a week(New York Heart Association Class II) without concomittent disease. These patients were checked pulmonary function test and metacholine provocation test before hemodialysis and same procedure was repeated if responsive, after hemodialysis. Results: 1) 12 out of 18 patients before hemodialysis were reactive in metacholine provocation test(66.7%) before hemodialysis. This airway hyperresponsiveness were decreased after hemodialysis. 2) Pulmonary function was improved after hemodialysis and change in $FEV_1$ was correlated with change in weight(r=-0.62, p<0.01). 3) There was a close correlation between log $PD_{20}$ and $FEF_{25}$, which is one of the variables of the peripheral airways(r=0.58, p<0.05). Conclusion: We speculated interstitial pulmonary edema may play a significant role in bronchial hyperresponsiveness and lung function impaired in patients with chronic renal failure.

• Journal of Chest Surgery
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• v.18 no.3
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• pp.517-528
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• 1985

Pulmonary function studies today are generally accepted as an integral part of the evaluation of poor-risk patients who are to have pulmonary surgery. The effect of various pulmonary surgery on lung function was investigated in 54 patients in whom comprehensive lung function test were performed before and between 2 months and 14 months after operation at the Department of Thoracic Surgery, Seoul National University Hospital. According to the result of analysis, the effect of pulmonary resection on forced flow rate was keeping with the change of lung volume, and the preoperative level of ventilatory function plays a major role in determining postoperative loss of functioning lung. Although all measures of expiratory flow [FVC, FEV1, FEFO.2-1.2, MEF50, FEF25-75] have the same percentage of reproducibility, but FEV1 shows most sensitive, reliable linear correlation with the functioning pulmonary tissue loss than other parameters. The linear regression lines derived from the correlation between preoperative [X] and postoperative [Y] FEV1 on various surgical procedures were as follows: 1. Y = 0.57X 0.03. in pneumonectomy group of lung cancer[r=0.84]. 2. Y = 0.56X + 0.33. in lobectomy group of lung cancer[r=0.79]. 3. Y = 0.69X + 0.25. in lobectomy group of pulmonary infection[r=0.91].

• Advances in Traditional Medicine
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• v.6 no.4
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• pp.330-335
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• 2006

The present investigation was carried out to determine the efficacy and safety of Abutilon indicum (A. indicum) (Eng: Country Mallow, Fam: Malvaceae) in patients of bronchial asthma. Dried aerial parts of A. indicum were finely powdered and given in the dose of 1 gm tid to 30 patients of either sex in the range of 15 - 80 years with mild to moderate bronchial asthma with or without any concurrent medication. The respiratory functions (FVC, $FEV_{1}$, $FEF_{25-75%}$and MVV) were assessed using a spirometer prior to and after 4 weeks of treatment. Efficacy of the drug in improving clinical symptoms and severity of asthmatic attacks was evaluated by interviewing the patient and by physical and hematological examination at the end of the treatment. 4 weeks treatment with the drug showed statistically significant improvement in various parameters of pulmonary functions in asthmatic subjects. Also significant improvement was observed in clinical symptoms and severity of asthmatic attacks. None of the patient showed any adverse effect with A. indicum. The results of the present study suggest the usefulness of A. indicum in patients with mild to moderate bronchial asthma.

• Journal of Sensor Science and Technology
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• v.13 no.2
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• pp.79-84
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• 2004

Asthma is one of the important respiratory diseases requiring home self care usually performed by commercialized peak expiratory flow meter (PEFM). However, this simple device can measure only single parameter, PEF, due to its purely mechanical principle, significantly limiting desease management quality. The present study introduced a new expiratory flow measurement technique by miniatured air expansion chamber easily installed within PEFM. Continuous pressure signal obtained from the chamber demonstrated an accurate quadratic relationship with flow. The volume measurement error was $<{\pm}1%$ well within the American Thoracic Society (ATS) criteria of 3%. Important spirometric parameters of FVC, PEF, and FEF25-75% were all accurately estimated with correlation coefficients > 0.95. The present technique obtains continuous expiratory air flow signal, making possible and convenient to perform spirometric test at home. Electronic interface capability would be also useful for remote asthma management.

• Journal of Chest Surgery
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• v.14 no.3
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• pp.187-194
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• 1981

Cardiac surgery is generally followed by a period of routine ventilator support. When the patient seems hemodynamically stable and relatively alert following surgery, respiratory adequacy is tested by the weaning trial. In this study, physiological and clinical prediction of postoperative respiratory adequacy, including values of pulmonary function tests, were examined in an attempt to identity those few variables which predicted the outcome of the ventilator weaning trial following surgery. Our series comprised 27 patients who underwent elective open intracardiac operations at the Department of Thoracic and Cardiovascular Surgery, School of Medicine, Kyungpook National University, from October 1979 to July, 1980. The pulmonary function tests performed on all patients included the following; forced vital capacity [FVC], forced expiratory volume [FEV1.0], forced expiratory flow [FEF 25--75~], residual volume [RV], and functional residual capacity [FRC], measured with a helium dilution technique. Of our 27 patients, 8 were successfully weaned within 20 hours of operation. All patients with cyanotic heart diseases or acquired heart diseases were unsuccessfully weaned. The bypass time in the successful weaning group was shorter in the mean value [82.8 minutes]than in the unsuccessful weaning group [120.5 minutes]. There was a relatively significant difference in the mean values for the two groups in arterial pressure, bleeding amounts and FiO2 among the postoperative monitoring variables, and in forced vital capacity [FVC]. The postoperative clinical assessments appeared vague but corresponded reasonably well to appraisal of success in weaning, especially in variables of cough and self-respiration efforts.