Reference values for lung function tests. I. Static volumes

Static lung volume (LV) measurements have a number of clinical and research applications; however, no previous studies have provided reference values for such tests using a healthy sample of the adult Brazilian population. Wi th this as our main purpose, we prospectively evaluated 100 non-smoking sub jects (50 males and 50 females), 20 to 80 years old, randomly selected from more than 8,000 individuals. Gender-specific linear prediction equations w ere developed by multiple regression analysis with total lung capacity (TLC ), functional residual capacity (FRC), residual volume (RV), RV/TLC ratio a nd inspiratory capacity (IC) as dependent variables, and with age, height, weight, lean body mass and indexes of physical fitness as independent ones. Simpler demographic and anthropometric variables were as useful as more co mplex measurements in predicting LV values, independent of gender and age ( R-2 values ranging from 0.49 to 0.78, P<0.001). interestingly, prediction e quations from North American and European studies overestimated the LV at l ow volumes and underestimated them at high volumes (P<0.05). Our results, t herefore, provide a more appropriate frame of reference to evaluate the nor malcy of static lung volume values in Brazilian males and females aged 20 t o 80 years.