The shape of the maximum expiratory flow volume curve

Differences in the shape of the maximum expiratory flow volume (MEFV) curve have been associated with pathologic states and physiologic differences between normal individuals. We describe variations in a new parameter, angle beta, which characterizes the general configuration of the MEFV curve among healthy subjects and subjects with disease in 5,140 white individuals. Women had consistently larger beta angles than men. There was a progressive decline in beta with advancing age. Cigarette smokers had lower beta angles than did lifetime never-smokers. Subjects with abnormal lung function patterns had lower beta angles than individuals with a normal pattern. Finally, individuals with asthma, chronic bronchitis, dyspnea and wheezing had significantly lower beta angles than healthy individuals. Further clinical and epidemiologic studies are needed to evaluate this measurement's possible value in pulmonary function evaluation.