Correlation of respiratory muscle strength with anthropometric variables of normal-weight and obese women.

Objective: To correlate anthropometric data and respiratory muscle strength (RMS) of normal-weight and obese women.
Methods: The sample consisted of 103 sedentary women, divided into two groups: 57 obese and 46 normal-weight women. Waist circumference (WC) and hip circumference (HC) were measured to calculate the waist-to-hip ratio (WHR), and maximal respiratory pressures (Pmax) were determined using an analog vacuum manometer to ± 300 cm H2O. Body composition was measured using tetrapolar bioelectrical impedance analysis. Descriptive statistics was used for data analysis, in addition to the Student t test for independent samples, Pearson correlation, and stepwise multiple linear regression analysis. Significance level was set at p ≤ 0.05.
Results: The analysis showed significant differences in Pmax of normal-weight women (PImax = -73.04±16.55 cm H2O and PEmax = 79.67±18.89 cm H2O) and obese women (PImax = -85.00±21.69 cm H2O and PEmax = 103.86±20.35 cm H2O). Anthropometric and manometric variables showed no significant correlation in both groups. When analyzing the influence of bioelectrical impedance on RMS, a positive correlation was observed between lean body mass and PImax.
Conclusion: Bioelectrical impedance and obesity showed a direct correlation with RMS. WC and WHR had no influence on RMS of obese women; however, a relevance to risk factors for associated diseases was observed. We believe that these results are due to an adjustment to excess body weight over the years.