Table 5. Correlation of the variables of respiratory mechanics, spirometry and static respiratory pressures with the body mass index.
| Variables |
Morbid obese
(n=50) |
Non-obese
(n=30) |
|||
|---|---|---|---|---|---|
| r | P | r | P | ||
| R0 (kPa/l/s) | 0.00009 | 0.9995 | 0.07414 | 0.6970 | |
| Rm (kPa/l/s) | 0.03030 | 0.8346 | 0.00081 | 0.9966 | |
| TR (kPa/l/s) | 0.1091 | 0.4506 | 0.4199 | 0.1209 | |
| R5 (kPa/l/s) | 0.03077 | 0.8320 | 0.05901 | 0.7567 | |
| R20 (kPa/l/s) | 0.1275 | 0.3777 | -0.1790 | 0.3438 | |
| X5 (kPa/l/s) | 0.06057 | 0.6760 | 0.1759 | 0.3526 | |
| f0 (Hz) | -0.02165 | 0.8813 | 0.4168 | 0.2219 | |
| AX (kPa/l*Hz) | -0.01857 | 0.8982 | 0.2543 | 0.1751 | |
| X5ins (kPa/l/s) | 0.01404 | 0.9229 | -0.03390 | 0.8589 | |
| X5 exp (kPa/l/s) | 0.00568 | 0.9687 | -0.1060 | 0.5773 | |
| ∆X5 (kPa/l/s) | -0.07194 | 0.6195 | -0.1080 | 0.5702 | |
| dR/dF | 0.04433 | 0.7599 | 0.2786 | 0.1360 | |
| FVC (L) | -0.04447 | 0.7591 | -0.3361 | 0.0694 | |
| FVC (% pred) | -0.3847 | 0.0058 | -0.2972 | 0.1107 | |
| FEV1 (L) | -0.02432 | 0.8669 | -0.2320 | 0.2174 | |
| FEV1 (% pred) | -0.3517 | 0.0122 | -0.06050 | 0.7508 | |
| FEV1/FVC (L) | -0.05293 | 0.7151 | -0.4029 | 0.0273 | |
| PF (L/s) | -0.2939 | 0.0383 | -0.3230 | 0.0817 | |
| PF (% pred) | -0.1123 | 0.4374 | -0.1225 | 0.5191 | |
| MVV (L) | -0.1098 | 0.4478 | -0.3298 | 0.0752 | |
| MVV (% pred) | -0.06098 | 0.6740 | -0.2338 | 0.2137 | |
| MIP (cmH2O) | -0.1951 | 0.1746 | -0.5408 | 0.0020 | |
| MIP (% pred) | -0.2941 | 0.0381 | -0.5191 | 0.1067 | |
| MEP (cmH2O) | -0.1746 | 0.6931 | -0.2949 | 0.1136 | |
| MEP (% pred) | -0.2715 | 0.0565 | -0.3627 | 0.0489 | |
FVC: forced vital capacity; FEV1: forced expiratory volume in the first second; PF: expiratory peak flow; MVV: maximal voluntary ventilation; MIP: maximal inspiratory pressure; MEP: maximal expiratory pressure. R0: resistance extrapolated for 0Hz; R5: resistance in 5Hz; R20: resistance in 20Hz; Rm: mean resistance; TR: tissue resistance; f0: resonance frequency; AX: reactance integral between 5Hz and resonance frequency; dR/dF: dependence of respiratory system resistance on frequency; X5ins: inspiratory reactance in 5Hz; X5exp: expiratory reactance in 5Hz; ∆X5: difference between inspiratory and expiratory reactance.