Exposure to Portland cement dust has long been associated with the prevalence of respiratory symptoms and varying degrees of airway obstruction in man. Apart from respiratory diseases, it was also found to be the cause of lung and laryngeal cancer, gastrointestinal tumours and also dermatitis. This study was done to investigate the effect of dust exposure on ventilatory lung function of Portland cement factory workers in Rawang, Selangor. Spirometry tests of 62 male workers (exposed to total dust concentration of 10,180 micrograms/m3 and PM10 of 8049 micrograms/m3) and 70 subjects from UPM (exposed to mean total dust of 192 micrograms/m3 and PM10 of 177 micrograms/m3--controls) revealed significant differences in spirometry values between the groups. The workers showed i) significantly lower FEV1% and FEF25-75%, and higher FMFT, ii) reduced FEV1% with increasing level of dust exposure and iii) higher prevalence of respiratory symptoms. Therefore, we suggest that exposure to dust in the cement factory leads to higher incidence of respiratory symptoms and impaired lung function.
Impairments of lung functionality as long-term effects of cigarette smoking have been well established. To our knowledge, no study on acute recovery patterns in any important lung function index after smoking a very limited number of cigarettes has ever been reported. The present study reports recovery patterns of lung transfer factor (TF) and related parameters in smokers and non-smokers who smoked two Camel cigarettes. Lung transfer factor and other indices were determined by the single breath-holding technique. From our results, the TF and related indices of healthy Malaysians are similar to previously published normals of comparable age. On smoking two cigarettes, male smokers began to recover from the 30th minute; male non-smokers had not begun recovery even by the 50th minute. Extrapolation of the recovery curves suggests that a "safer" interval between cigarettes for male smokers is about 114 minutes.
A study was carried out to determine ventilatory capacity (Forced Expiratory Volume or FEV1 and Forced Vital Capacity or FVC) in apparently normal Malay office workers in Malaysia. The subjects, 78 males and 113 females, were interviewed using a standardized questionnaire to exclude those with symptoms or past history of cardiopulmonary disease. Measurements of age, height, weight, FEV, and FVC were made on each subject; the FEV, and FVC were measured using Vitalograph spirometers. The mean FEV, and FVC for males were 3.35 litres and 3.76 Iitres, respectively. For females, the mean FEV, and FVC were 3.46 and 2.72 Iitres, respectively. Height was positively correlated with FEV, and FVC (p
Several equations have been used to predict lung function standard results for different populations. It is important lung function evaluations use appropriate standards for the study population. The objective of this study was to develop a prediction equation for lung function test results for the Malaysian population. Spirometry was performed among 5,708 subjects and 1,483 healthy, lifetime never smoked subjects (386 males and 1,097 females). Prediction equations were derived for both men and women for FVC and FEV1 results. The equations were validated on new subjects (n = 532, 222 males and 310 females) who met the same inclusion and exclusion criteria as the main cohort. There was a positive correlation between the measured values and the values derived from the new prediction equations (0.62 for FEV1 and between 0.66 and 0.67 for FVC; both p < 0.05) for both men and women with a smaller bias and limit of agreement compared to the published reference equations of ECCS, Knudson, Crapo and NHANES III. The reference equations derived from local spirometry data were more appropriate than generally used equations based on data from previous studies in different population.
We conducted a study to measure the peak expiratory flow rate (PEFR), forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) in a group of normal Malay primary school children aged 7 to 12 years. PEFR was measured in 920 children (482 boys and 438 girls) while FVC and FEV1 were measured in 292 of them (168 boys and 124 girls). In agreement with previous studies, we found that PEFR was correlated with age and height of the subjects but FVC and FEV1 were correlated with height only. Prediction equations for all 3 lung function indices for Malay boys and girls were formulated. In comparison with the lung function values from Western and Chinese subjects, the lung function values in our subjects are lower.
A study was undertaken to produce reference values of lung function in Chinese children and a means of calculating adjusted standard deviation scores of lung function for Malay and Indian ethnic groups.
Spirometry was performed on 1,485 male subjects ranging in age from 13 years to 78 years and comprising of all the main ethnic groups in Malaysia. They were divided into six age categories. Mean forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) were 3.45 +/- 0.02 and 3.10 +/- 0.02, respectively. Both FVC and FEV1 correlated negatively with age. Regression analysis revealed an age-related decline in FVC of 295 ml per decade of life. Multiple stepwise regression of the data for the prediction of an individual's FVC above the age of 20 years gave the equation FVC (1) = 0.0404 (height in cm)-0.0295 (age in years)-2.2892. Predicted FVC values derived from equations based on other populations were considerably higher than the observed mean in this study. This study therefore, reemphasises the need to be cautions when applying formulae derived from one population to another. Grossly erroneous conclusions may be reached unless predicted equations for lung-function tests for a given population group are derived from studies based upon the same population group.
This study was conducted on 506 firemen in Singapore. Interviews, pulmonary function tests and audiometry were conducted. With regard to pulmonary function, the results showed that forced vital capacity (FVC) increased up to the age of 25-30 years for both Chinese and Malays. Both FVC and forced expiratory volume in one second (FEV1.0) increased with standing height over the whole age range studied. The mean values of FVC and FEV1.0 were higher in Chinese. It was also found that the FEV1 of the subjects in the study showed a greater decline in rate with age than other workers studied by the authors previously. The hearing threshold of 83 fire fighters showed a prominent upward shift of 6-8 KHz at ages 20-30. This upward shift was more pronounced in the right ear. The implications of the findings are discussed and a comparison with results of other similar studies in other countries is made.
Prediction equations for peak expiratory flow rate (PEFR) of Malay, Chinese and Indian children were obtained by analysing 1020 PEFR recordings of children free of respiratory symptoms and illnesses. Boys had significantly higher PEFR than girls. For both sexes the highest levels of PEFR were observed in Malays and the lowest in Indians. The differences between Malay and Chinese boys were not statistically significant but the levels of PEFR for Malay and Chinese boys were significantly higher than those for Indian boys. In girls the differences among the ethnic groups were not statistically significant. Although ethnic differences were observed in boys these differences might not be clinically important. A common prediction equation for each sex should be both practical and accurate. When compared with predicted levels for white American and Australian children the predicted levels of PEFR of Malaysian children were found to be lower; these differences could be clinically important and the use of standards for Western children when assessing Malaysian children might not be appropriate.
BACKGROUND AND OBJECTIVE: Although the multi-ethnic European Respiratory Society/Global Lung Initiative (ERS/GLI) 2012 reference values have been developed, the Taskforce has called for further validation specifically on subpopulations that were under represented such as the Malays, Chinese and Indians, in which the two latter ethnic groups represent about one-third of the world population. Thus, the aims of this study were to evaluate the appropriateness of the ERS/GLI 2012 reference values in a healthy adult Malaysian population and to construct a local lung function reference for the Malaysia population specific to the three major ethnic groups.
METHODS: Acceptable spirometry data were obtained from 30 281 healthy subjects aged 35-70 years comprising Malays, Chinese and Indians from the Malaysian Cohort. Local reference values were calculated using regression analysis and evaluated using ERS/GLI reference values to obtain GLI Z-scores.
RESULTS: The mean (SD) of the forced expiratory volume in 1 s (FEV1 ) for males were 2.67 (0.46), 2.89 (0.48) and 2.60 (0.46) and females were 1.91 (0.36), 2.13 (0.37) and 1.86 (0.35) for Malays, Chinese and Indians, respectively. For forced vital capacity (FVC), the mean (SD) for males were 3.03 (0.53), 3.28 (0.58) and 2.92 (0.53) and females were 2.15 (0.40), 2.38 (0.43) and 2.07 (0.41) for Malays, Chinese and Indians, respectively. The mean GLI Z-scores were less than -0.5 for FEV1 and FVC and more than 0.5 for FEV1 /FVC. A large percentage of subjects in all the three ethnic groups were defined lower than the lower limit of normal.
CONCLUSION: This present and large multi-ethnic Asian-based study demonstrates clinically significant deviation from ERS/GLI 2012 equations for spirometry. It highlights the importance of validating predicted equations for spirometry in local populations.
Aerobic capacity (VO2max) and lung capacities were measured in 66 healthy females ranging in age from 13 to 49 years. Forced vital capacity (FVC) and peak expiratory flow rate (PEFR) were measured using a dry spirometer and Wrights peak flow meter respectively. Cardiopulmonary parameters were obtained from a progressive ergocycle test to exhaustion. Mean FVC and PEFR obtained were 2.73 +/- 0.07 L and 412 +/- 8.5 L/min respectively. FVC correlated negatively with age in subjects from the 3rd to 5th decade of age (r = 0.38, p < 0.05). Mean VO2max was 43.2 +/- 0.9 ml/kg/min in the 2nd decade compared to 30.3 +/- 0.7 ml/kg/min in the fifth decade. Regression analysis revealed an age related decline in VO2max of 0.45 +/- 0.8 ml/kg/min/year, which was found to be somewhat higher compared to other studies.
Cardiorespiratory adjustments to maximal treadmill exercise were studied in young untrained Malaysia men representative of the three major ethnic groups in Malaysia and Singapore. Maximal values for oxygen uptake and cardiac performance were essentially similar In the three groups and were comparable to those reported for other populations.
Understanding the mechanisms underlying the process of regeneration and repair of airway epithelial structures demands close characterization of the associated cellular and molecular events. The choice of an animal model system to study these processes and the role of lung stem cells is debatable since ideally the chosen animal model should offer a valid comparison with the human lung. Species differences may include the complex three-dimensional lung structures, cellular composition of the lung airway as well as transcriptional control of the molecular events in response to airway epithelium regeneration, and repair following injury. In this paper, we discuss issues related to the study of the lung repair and regeneration including the role of putative stem cells in small- and large-animal models. At the end of this paper, the author discuss the potential for using sheep as a model which can help bridge the gap between small-animal model systems and humans.
Spirometric recordings of 1098 Malaysian children who were free of respiratory symptoms were examined by least square regression analysis of log-transformed lung function data. Ethnic differences were observed in FVC, FEV1, and FEF25-75 independent of father's education, exposure to passive smoking, wood stove, kerosene stove and mosquito repellents, family history of chest illness and history of allergy, after adjusting for standing height, age and sex. Exposure to kerosene stove was significantly associated with reduced FVC and FEV1 indicating that environmental factors may impair lung function in symptomless children. Prediction equations were derived for each ethnic group and sex. Comparison with data from the literature showed that Malaysian children had lower lung function values than Caucasian children. Generally, Chinese children had higher FEV1, FVC and FEF25-75 than Malay and Indian children. Indian children consistently had the lowest lung function values. Since these ethnic differences were independent of environmental and other host factors, anthropometric variations could be an explanation.
Pulmonary function tests have been evolved as clinical tools in diagnosis, management and follow up of respiratory diseases as it provides objective information about the status of an individual's respiratory system. The present study was aimed to evaluate pulmonary function among the male and female young Kelantanese Malaysians of Kota Bharu, Malaysia, and to compare the data with other populations.