The maximal expiratory flow-volume curve in normal subjects in India.

Data on pulmonary function, with particular reference to flow-volumes, were obtained in 760 normal healthy Indians in Bombay, who had never smoked and who had no symptom or history of cardiorespiratory disease. Prediction equations were derived for spirometric parameters and for maximal expiratory flows. The maximal expiratory flow-volume curves showed considerable intersubject variability. Both flow and volume decreased with advancing age, with the flow-volume curve appearing increasingly convex towards the volume axis in its second half with increase in age. The maximal expiratory flows in our study were significantly lower compared to values reported by workers in the West.