Background Chronic Obstructive Pulmonary Disease (COPD) is a set of diseases, has as its main characteristics a limitation of the ventilatory flow. The World Health Organization (WHO) estimates that by 2030, COPD will be the third-largest cause of death. However, for the effective diagnosis, it is necessary to use reference curves appropriate to the population in which the individual belongs, thus it is possible to identify probable limits and abnormalities.Methods This is a cross-sectional and retrospective study conducted in a metropolitan region comprising 29 municipalities in southern Brazil. Individuals of both genders aged between 18 and 59 years, non-smokers, self-identified with white skin, participated in the study. The spirometric collections were done following the American Thoracic Society guidelines. And beyond them, mass and height were collected for determination of the Body Mass Index. The correlations between pulmonary and anthropometric variables were tested by regression analysis univariate after the selection of variables through multivariate analysis and logarithmic regression.Results In this sample, 800 participants were evaluated, of these 533 females and 267 males. Both sexes had considerable spirometry variables values as FVC, FEV6, and FEV1, used in the development of prediction models. The only variable, with a positive correlation in both genders, was height. For the males model, the best fit variable was FVC, with R 2 = 0.417 and for females FEV, with R 2 = 0.462. Among males, was seeing a lower value for all individuals in both variables. Whereas women had similar behavior, for CVS, with slight differences in the ends of the curves, comparing FEV1, the values were higher in all evaluated.Conclusion The prediction equations showed the previous curves were very restrictive and could be leading to false-positives. Thus, this update in the reference values would support clinical decisions on the prevention, diagnosis, and treatment of COPD.
