Changes In The Shape Of The Maximal Expiratory Flow-Volume Curve Following Weight Loss In Obese Females

Though the effects of obesity on cardiovascular health are well-studied, less is known in regards to the effect of obesity on the respiratory system. The buildup of fat leads to a decrease in chest well compliance and increase in airway resistance, both of which are determinants to expiratory air flow. Thus, it seems reasonable that following weight loss, the shape of the maximal expiratory flow-volume (MEFV) curve will be altered, indicating an improvement in respiratory function. This project examined the shape of the MEFV curve in obese females before and after completing a weight loss program. We hypothesized that the shape of the MEFV curve in obese females would be altered, as assessed using the beta angle (ß°), flow ratio (FR), slope ratio (SR), and are-under-the-curve (AUC) techniques. A significant difference was observed in SR at 80% and 75% of forced vital capacity, as well as in certain AUC segments. A change in the shape of the MEFV curve occurs following weight loss. These data suggest that obese females may improve their ventilatory reserve for increasing ventilation during exercise as a result of weight loss.