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Table 2 Body composition parameters determined by dual-energy x-ray absorptiomtry, in-built Tanita BIA 8 equations, and published equations

From: Bioelectrical impedance analysis to estimate body composition, and change in adiposity, in overweight and obese adolescents: comparison with dual-energy x-ray absorptiometry

Method DXA Tanita BIA8 Ramirez et al. [[11]] Bray et al. [[12]] Jaffrin et al. [[14]]
Fat-free mass kg
Mean ± SD (kg) 47.4 ± 11.7 51.7 ± 12.1a 48.0 ± 11.1 47.8 ± 9.8 48.3 ± 11.5
Bias (kg)   4.3 0.6 0.4 0.9
Limits of agreement (kg)   -5.3 to 13.9 -7.1 to 8.2 -7.6 to 8.4 -6.2 to 8.0
r c (95% CI)b   0.86 (0.79 – 0.91) 0.94 (0.90 – 0.96) 0.93 (0.89– 0.6) 0.95 (0.92 – 0.97)
Fat mass kg
Mean ± SD (kg) 41.8 ± 12.1 37.5 ± 13.0a 41.2 ± 11.5 41.3 ± 12.2 40.9 ± 11.6
Bias (kg)   -4.3 -0.6 -0.5 -0.9
Limits of agreement (kg)   -13.9 to 5.3 -8.2 to 7.1 8.4 to -7.6 8.0 to -6.2
r c (95% CI)b   0.87 (0.81 – 0.92) 0.94 (0.91 – 0.96) 0.94 (0.91 – 0.96) 0.95 (0.92 – 0.97)
Percentage of body fat
Mean ± SD (%) 46.4 ± 7.4 41.4 ± 8.3a 45.8 ± 5.5 45.7 ± 5.2 45.6 ± 6.0
Bias (%)   -5.0 -0.6 -0.5 -0.8
Limits of agreement (%)   -15.1 to 5.0 -9.1 to 7.9 -9.2 to 8.0 -9.2 to 7.4
r c (95% CI)b - 0.65 (0.53 – 0.75) 0.77 (0.67 - 0.85) 0.76 (0.65 – 0.83) 0.79 (0.69 – 0.86)
  1. adifference between DXA and Tanita BIA8, P <0.001.
  2. bCI: confidence interval.