Linear equations for primary indices of lung function including terms for body composition
| Index | Partial regression coefficients | Constant | RSD3-150 | Variance3-150 | ||||
|---|---|---|---|---|---|---|---|---|
| Age3-151 | Stature | BMI3-152 | Fat % | FFMI | ||||
| TLC | ||||||||
| Women | NS | 7.82 | –0.038 | NS | –5.92 | 0.52 (0.54) | 0.61 (0.56) | |
| Men | 0.025 | 9.64 | – 0.051 | 0.0583-154 | –11.1 | 0.64 (0.67) | 0.47 (0.42) | |
| IC | ||||||||
| Women | NS | 3.84 | NS | 0.084 | –5.06 | 0.36 (0.38) | 0.40 (0.31) | |
| Men | NS | 3.44 | NS | 0.13 | –5.16 | 0.48 (0.53) | 0.28 (0.12) | |
| FRC | ||||||||
| Women | NS | 4.06 | –0.090 | –1.46 | 0.46 (0.56) | 0.53 (0.29) | ||
| Men | 0.019 | 5.95 | –0.086 | –5.53 | 0.59 (0.64) | 0.39 (0.26) | ||
| ERV | ||||||||
| Women | –0.018 | 1.40 | –0.058 | 1.19 | 0.33 (0.39) | 0.58 (0.41) | ||
| Men | NS | 3.69 | –0.079 | –2.57 | 0.46 (0.50) | 0.37 (0.24) | ||
| RV | ||||||||
| Women | 0.024 | 2.56 | –0.025 | NS | –2.63 | 0.30 (0.32) | 0.41 (0.32) | |
| Men | 0.033 | 2.57 | –0.017 | NS | –3.81 | 0.33 (0.34) | 0.37 (0.34) | |
| FVC | ||||||||
| Women | –0.018 | 4.84 | –0.030 | NS | –2.57 | 0.46 (0.47) | 0.61 (0.58) | |
| Men | –0.011 | 6.76 | –0.047 | 0.069 | –6.70 | 0.52 (0.55) | 0.55 (0.50) | |
| FEV1 | ||||||||
| Women | –0.022 | 3.05 | –0.022 | NS | –0.47 | 0.35 (0.37) | 0.66 (0.63) | |
| Men | –0.026 | 4.80 | –0.031 | 0.041 | –3.61 | 0.48 (0.49) | 0.57 (0.54) | |
| Tlco | ||||||||
| Women | –0.030 | 7.47 | 2.543-152 | NS | 0.203-154 | –9.68 | 1.23 (1.26) | 0.44 (0.40) |
| Men | –0.072 | 10.49 | 2.713-152 | NS | 0.123-154 | –11.98 | 1.33 (1.34) | 0.48 (0.47) |
TLC = total lung capacity; IC = inspiratory capacity; FRC = functional residual capacity; ERV = expiratory reserve volume; RV = residual volume; FVC = forced vital capacity; FEV1 = forced expiratory volume in one second; Tlco = carbon monoxide transfer factor; NS = not significant and variable omitted on this account.
↵3-150 Term without allowance for body composition is given in parentheses. In each instance the difference is significant.
↵3-151 Effects on partial regression coefficients on age of allowing for fat% and FFMI age are given in table 5.
↵3-152 In case of Tlco the coefficient is that on Va/St2, not BMI.
↵3-154 Coefficient significant at 5% but not at 1% level of probability.