In China there are 1,923,842 Korean Chinese, who live mostly (92.27%) in the country's three northeast provinces. In spite of this sizeable number, no spirometric data are available at present on them. The present study investigated normal spirometric reference values for the Korean Chinese children and adolescents. Spirometry was performed in 443 healthy Korean Chinese children and adolescents aged 8-18 yr with measurements of forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), peak expiratory flow (PEF) and maximum mid-expiratory flow (MMEF). Reference equations for FEV1, FVC, PEF and MMEF were derived by using multiple regression analysis. All of the measured spirometric parameters correlated positively with height and age significantly (P < 0.001). The predicted values of FVC and FEV1 were higher than values obtained by using Caucasian and other Asian equations (P < 0.001). A set of spirometric reference equations has been derived using a relatively large, healthy, non-smoking young Korean Chinese population with a wide range of ages and heights, the results of which differ from those gained from several other reference equations. These reference equations should be used for evaluation of lung function in this population.
Adolescent ; Child ; China ; Female ; *Forced Expiratory Volume ; Humans ; Lung/*physiology ; Male ; Maximal Expiratory Flow Rate ; Peak Expiratory Flow Rate ; Reference Values ; Republic of Korea/ethnology ; Spirometry/*standards ; *Vital Capacity

OBJECTIVETo study the development of pulmonary function of healthy children between 1-48 months.

METHODSA total of 295 healthy children at ages of 1-48 months were classified into 7 groups according to their age, i.e., 1-2 months, 3-4 months, 5-7 months, 8-12 months, 13-24 months, 25-36 months, and 37- 48 months. Pediatric pulmonary function laboratory type 2600 (Sensor Medics Corporation USA) was used to detect tidal flow volume curve, which can partially replace the maximum expiratory flow volume curve and reflect airway ventilation function. Passive expiratory flow volume technique was used to examine respiratory system static compliance and total airway resistance. Open nitrogen washout method was used to measure functional residual capacity.

RESULTSThe values of tidal, peak tidal expiratory flow, and respiratory system static compliance functional residual capacity increased with the increasing age and were significantly different among the 7 groups. However, respiratory rate and total airway resistance decreased with the increased age. The value of each parameter of tidal flow volume curve was stable during 1-48 months.

CONCLUSIONSThis study displayed the developmental characteristics of pulmonary function of healthy children at ages of 1-48 months, which is useful to observe the changes of pulmonary function in respiratory diseases.

Age Factors ; Child, Preschool ; Female ; Functional Residual Capacity ; Humans ; Infant ; Lung ; physiology ; Male ; Peak Expiratory Flow Rate

OBJECTIVETo propose a new method for acquiring pulmonary function parameters based on measurement of volume changes of thoracic impedance.

METHODSWe studied the relationship between the volume changes of thoracic impedance and pulmonary function parameters during forced breathing based on bioimpedance measurement, and developed an instrument for measuring thoracic impedance. Using this instrument and a MRI spirolab III lung function test instrument, both based on flowmeter measurement, we measured such pulmonary function parameters including forced vital capacity (FVC), forced expiratory volume in one second/FVC (FEV1/FVC), and peak expiratory flow in 10 healthy volunteers and compared the measurement results.

RESULTSThe differences in the parameters measured using the two instruments were all within two folds of the positive and negative standard deviations of the average values, demonstrating good consistency in the measurement between the two methods.

CONCLUSIONSThe measurement results of the bioimpedance-based instrument we developed show good consistency with those by the commercially available pulmonary function test instrument.

Adult ; Electric Impedance ; Forced Expiratory Volume ; Humans ; Peak Expiratory Flow Rate ; Respiratory Function Tests ; methods ; Thorax ; physiology ; Vital Capacity ; Young Adult

Acute Disease ; Adolescent ; Age Factors ; Asthma ; diagnosis ; physiopathology ; Bronchi ; physiology ; Child ; Child, Preschool ; Female ; Forced Expiratory Volume ; Humans ; Infant ; Male ; Peak Expiratory Flow Rate

OBJECTIVETo investigate the lung function of the normal subjects living in Hebei province and its correlative factors such as living circumstance, age, height, and body weight.

METHODSThe lung volumes and breath capacities of 1,587 normal subjects were tested by portable spirometers (Scope Rotry) from August to October in 2002. The influences of living circumstance, age, gender, height, and body weight on lung functions were observed and analyzed.

RESULTSNo significant difference was found between urban and rural areas in all indexes (P > 0.05); however, significant difference existed between male and female subjects (P = 0.000). The change trends of lung function in male and female subjects were similar. Growth spurt appeared at the age of 12-16 years in male subjects and 12-14 years in female subjects. Vital capacity (VC), forced vital capacity (FVC), and forced expiratory volume in one second (FEV1) reached their peaks at the age of 26-34 years and then decreased with age. Peak expiratory flow (PEF), 25% forced expiratory flow (FEF50%), and 75% forced expiratory flow (FEF75%) appeared at the age of 18 and then went down with age. Both height and weight had a correlation with all the indexes of lung functions, although the influence of height is stronger than weight.

CONCLUSIONSAll the indexes of lung function have correlations with age, height, and weight. Lung function changes with aging, therefore different expected values shall be available for the adolescence, young adults, and middle-aged and old people. This study provides reference values of lung function for normal population.

Adolescent ; Adult ; Aged ; Child ; Female ; Forced Expiratory Flow Rates ; Forced Expiratory Volume ; Humans ; Lung ; physiology ; Male ; Middle Aged ; Peak Expiratory Flow Rate ; Reference Values ; Respiratory Function Tests ; Rural Health ; Sampling Studies ; Urban Health ; Vital Capacity

The aim of this study is to develop backpropagation neural networks (BPNN) for better prediction of ventilatory function in children and adolescents. Nine hundred and ninety-nine healthy children and adolescents (500 males and 499 females) aged 10-18 years, all of the Han Nationality, were selected from Inner Mongolia Autonomous Region, and their heights, weights, and ventilatory functions were measured respectively by means of physical examination and spirometric test. Using the approaches of BPNN and stepwise multiple regression, the prediction models and equations for forced vital capacity (FVC), forced expiratory volume in one second (FEV1), peak expiratory flow (PEF), forced expiratory flow at 25% of forced vital capacity (FEF25%), forced expiratory flow at 50% of forced vital capacity (FEF50%), maximal mid-expiratory flow (MMEF) and forced expiratory flow at 75% of forced vital capacity (FEF75%) were established. Through analyzing mean squared difference (MSD) and correlation coefficient (R) of the ventilatory function indexes, the present study compared the results of BPNN, linear regression equation based on this work (LR's equation), prediction equations based on the studies of Ip et al. (Ip's equation) and Zapletal et al. (Zapletal's equation). The results showed, regardless of sex, the BPNN prediction models appeared to have smaller MSD and higher R values, compared with those from the other prediction equations; and the LR's equation also had smaller MSD and higher R values compared with those from Ip's and Zapletal's equations. The coefficients of variance (CV) for FEF50%, MMEF and FEF75% were higher than those of the other ventilatory function parameters, and their increasing percentages of R values (ΔR, relative to R values by LR's equation) derived by BPNN were correspondingly higher than those of the other indexes. In sum, BPNN approach for ventilatory function prediction outperforms the traditional regression methods. When CV of a certain ventilatory function parameter is higher, the superiority of BPNN would be more significant compared with traditional regression methods.
Adolescent ; Child ; China ; Female ; Forced Expiratory Volume ; physiology ; Forecasting ; Humans ; Lung ; physiology ; Male ; Neural Networks (Computer) ; Peak Expiratory Flow Rate ; physiology ; Pulmonary Ventilation ; physiology ; Reference Values ; Sampling Studies ; Vital Capacity ; physiology

BACKGROUND: Several investigators have demonstrated a considerable disagreement between FEV1 and PEFR to assess the severity of airflow obstruction. The purpose of this study was to examine whether the discrepancy between the two measurements affects the assessment in the severity of acute asthma. METHODS: Thirty-five consecutive asthma patients measured both FEV1 and PEFR at 0, 1hr, 1, 3, 5, 7 days of an emergency room admission using a spirometer and a Ferraris PEFR meter. The degree of discrepancy between FEV1 and PEFR expressed as % predicted values was determined. RESULTS: When predictive equations that recommended by the instrument manufacturers were used, PEFR measured with the PEFR meter (f-PEFR) was significantly higher than FEV1 at all time points, with 16.1% mean difference and unacceptable wide limits of agreement (-20.0~52.3%). The classification in severity was significantly different between FEV1 and f-PEFR (p < 0.001). The discrepancy was inter-instrumental in large part because f-PEFR was 10.1% higher than spirometric PEFR. Different predictive equations altered the degree of the differences but could not completely correct it. CONCLUSION: These results indicate that f-PEFR values underestimate the severity of airflow obstruction in acute asthma despite using recommended predictive equations. Therefore, these confounding factors should be considered when the severity of airflow obstruction is assessed with PEFR.
Acute Disease ; Adult ; Aged ; Airway Obstruction/diagnosis/*physiopathology ; Asthma/*physiopathology ; Comparative Study ; Female ; Forced Expiratory Volume/physiology ; Human ; Male ; Middle Age ; Peak Expiratory Flow Rate/*physiology ; Predictive Value of Tests

OBJECTIVES: Nitrogen dioxide (NO2) has been inconsistently associated with gradual decreases in lung function. Here, we studied the effects of NO2 exposure in asthmatics by examining the association between changes in lung function and concentrations of NO2 which were personally measured. METHODS: Peak expiratory flow (PEF) and daily personal exposures to NO2 were recorded on 28 patients with asthma (confirmed by methacholine provocation test) over 4 weeks. We used generalized estimating equations to assess the relationship between personal NO2 exposure and PEF, adjusting for potential confounders such as age, gender, outdoor particulate matter, temperature, humidity, and exposure to environmental tobacco smoke. RESULTS: The personal NO2 exposures were higher than the corresponding ambient levels. The mean personal: ambient ratio for NO2 was 1.48. The personal NO2 exposures were not associated with the morning PEF, evening PEF, or the diurnal PEF variability. However, environmental tobacco smoke was negatively associated with both the morning and evening PEF. CONCLUSIONS: Among the asthmatic adults who participated in this study, we found no apparent impact of personal NO2 exposures on the peak expiratory flow.
Tobacco Smoke Pollution/adverse effects/analysis ; Time Factors ; Peak Expiratory Flow Rate/*drug effects ; Nitrogen Dioxide/*adverse effects ; Male ; Lung/*drug effects/physiology ; Korea/epidemiology ; Inhalation Exposure/*adverse effects/analysis ; Humans ; Female ; Asthma/epidemiology/*physiopathology ; Air Pollution, Indoor/adverse effects/analysis