Ethnic Differences in Normal Spirometric Lung Function of Malaysian Children

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.