Predictive Equations for Maximum Respiratory Pressures of Women According to Body Mass.

BACKGROUND The objective of the present study was to develop predictive equations for maximum respiratory pressures in women according to anthropometric characteristics. METHODS This cross-sectional study included 156 women between ages 25 and 65 y with a body mass index (BMI) between 18.5 and 55 kg/m2), who were evaluated for body mass, height, BMI, neck circumference, waist circumference, hip circumference, and waist/hip ratio. Respiratory muscle strength was assessed by measuring the maximum inspiratory pressure (P(Imax)) and maximum expiratory pressure (P(Emax)) with an analog vacuum manometer. For statistical analysis, the Kolmogorov-Smirnov test, Spearman correlation test, and stepwise multiple regression were used. The level of statistical significance was set at 5% (P < .05). RESULTS Body mass, BMI, neck circumference, waist circumference, hip circumference, and waist/hip ratio showed significant and positive correlations with P(Imax) and P(Emax). On the other hand, age and height showed no significant correlations with P(Imax) and (P(Emax)). In the regression analysis, the variables that correlated significantly with P(Imax) and P(Emax) were used. CONCLUSIONS Body mass was the variable that best contributed to predicting maximum respiratory pressures values in women (11.70% of the variations of the P(Imax) and 21.05% of the variations of the P(Emax)). For P(Imax) measurements, the equation -0.2 × body mass - 65.6 was established, and for P(Emax), the equation 0.3 × body mass + 66.4 was used. It is suggested that the predictive equations developed in this study can be used in the interpretation of the assessment of respiratory muscle strength in morbidly obese women 25-65 y of age.