Table 3.
Ratio with simplified model | E/I value | |||||
---|---|---|---|---|---|---|
0.8 | 0.9 | 0.95 | 1.0 | 1.1 | Variability | |
FFM density = (1.569 + 1.16 × E/I)/(1.396 + 1.08 × E/I) |
1.105 | 1.103 | 1.103 | 1.102 | 1.101 | 0.36% |
TBK/BCM = 106.4 + 2.8 × (E/I) |
108.6 | 108.9 | 109.1 | 109.2 | 109.5 | 0.81% |
TBW/FFM = (1 + E/I)/(1.569 + 1.16 × E/I) |
0.721 | 0.727 | 0.730 | 0.733 | 0.738 | 2.3% |
TBW/LST = (1 + E/I)/(1.488 + 1.080 × E/I) |
0.765 | 0.772 | 0.776 | 0.779 | 0.785 | 2.6% |
Ms/TBW = (0.0162 + 0.0095 × E/I)/(1 + E/I) |
0.0132 | 0.013 | 0.0129 | 0.0129 | 0.0127 | 3.9% |
TBPro/FFM =(0.445 + 0.069 × E/I)/(1.569 + 1.16 × E/I) |
0.200 | 0.194 | 0.191 | 0.188 | 0.183 | 8.9% |
TBK/FFM = (152 + 4 × E/I)/(1.569 + 1.16 × E/I) |
62.2 | 59.5 | 58.3 | 57.2 | 55.0 | 12.3% |
BCM/FFM = 1.429/(1.569 + 1.16 × E/I) |
0.572 | 0.547 | 0.535 | 0.524 | 0.502 | 13.1% |
Body component ratios: BCM/FFM, ratio of body cell mass to fat-free mass (in kg/kg); FFM density, fat-free mass density (in kg/L); Ms/TBW, ratio of soft-tissue minerals to total body water (in kg/kg); TBK/BCM, ratio of total body potassium to body cell mass (in mmol/kg); TBK/FFM, ratio of total body potassium to fat-free mass (in mmol/kg); TBPro/FFM, ratio of total body protein to fat-free mass (in kg/kg); TBW/FFM, ratio of total body water to fat-free mass (in kg/kg); TBW/LST, ratio of total body water to lean-soft tissue (in kg/kg).
Abbreviation: E/I, ratio of extracellular water to intracellular water (in kg/kg).
Variability of body component ratio: For instance, the relative variability of TBW/FFM ratio can be calculated as [(TBW/FFM at E/I 1.1) – (TBW/FFM at E/I 0.8)]/(TBW/FFM at E/I 0.95) = (0.738 − 0.721)/0.730 = 2.3%.