Respiratory health survey in an Indian South African community : distribution and determinants of symptoms, diseases and lung function.
A cross-sectional epidemiologic survey of the respiratory health status was conducted in the adult (15 years and older) Indian South African population resident in Lenasia, Johannesburg to study the distribution and determinants of respiratory symptoms, disease and lung function level. A slightly modified self-administered version of a standardised respiratory health questionnaire and a wedge spirometer was used. There were a high proportion of current smokers among men. Although women smoked less than men in other communities they nevertheless smoked on average more heavily than other Indian South African women. Indian men and women who smoked had a high prevalence of respiratory symptoms. The women also demonstrated an increased susceptibility to the effects of cigarette smoking when compared with women in other communities. Indians in this study had spirometric lung function levels that were lower than that recorded in recent studies in Blacks and Whites in South Africa. Respiratory symptoms, disease and lung function level were examined in a multiple logistic regression model which contained all the potential determinants recorded in the present study. Voluntary tobacco smoking, recent chest illnesses and any kind of heart trouble was associated with a significant risk for having most of the respiratory symptoms and diseases in men and women. In addition exposure to dust in the work environment, little or no exercise,>Std. 8 education a history of any kind of chest trouble and respiratory trouble before the age of 16 years was associated with an increased risk for having respiratory symptoms in men in this model. An increased risk for respiratory symptoms was demonstrated in women only with age. Age and standing height were the most important determinants of lung function level in men and women in the regression model. Dust exposure in the work environment was associated with a significantly lower lung function level in men. Alcohol consumption and a history of whooping cough was also independently associated with a lower lung function level in men but were of borderline significance. In women involuntary /passive tobacco smoke exposure and respiratory trouble before the age of 16 years were associated with a lower lung function level. Women who spent most of their lives in a rural area and those who had a university education had a higher lung function level. The deleterious effects of smoking on lung function were minimal in this study possibly because lung function was performed only in subjects in the 18-45 year age category. A "healthy smoker" effect was demonstrated in men. Men who ever smoked and were without cardiorespiratory symptoms had significantly higher lung function levels compared to men who never smoked and were without symptoms.