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Influence of posture and frequency modes in total body water estimation using bioelectrical impedance spectroscopy in boys and adult males.

Kagawa M, Wishart C, Hills AP - Nutrients (2014)

Bottom Line: While TBW estimated from the MF mode was comparable, extra-cellular fluid (ECF) and intra-cellular fluid (ICF) values differed significantly (p < 0.01) between the different postures in both groups.Measurement posture may not affect estimation of TBW in boys and adult males, however, body fluid shifts may still occur.In addition, technical factors, including selection of prediction equation, may be important when TBW is estimated from measured impedance.

View Article: PubMed Central - PubMed

Affiliation: Institute of Nutrition Sciences, Kagawa Nutrition University, Saitama 350-0288, Japan. mskagawa@eiyo.ac.jp.

ABSTRACT
The aim of the study was to examine differences in total body water (TBW) measured using single-frequency (SF) and multi-frequency (MF) modes of bioelectrical impedance spectroscopy (BIS) in children and adults measured in different postures using the deuterium (2H) dilution technique as the reference. Twenty-three boys and 26 adult males underwent assessment of TBW using the dilution technique and BIS measured in supine and standing positions using two frequencies of the SF mode (50 kHz and 100 kHz) and the MF mode. While TBW estimated from the MF mode was comparable, extra-cellular fluid (ECF) and intra-cellular fluid (ICF) values differed significantly (p < 0.01) between the different postures in both groups. In addition, while estimated TBW in adult males using the MF mode was significantly (p < 0.01) greater than the result from the dilution technique, TBW estimated using the SF mode and prediction equation was significantly (p < 0.01) lower in boys. Measurement posture may not affect estimation of TBW in boys and adult males, however, body fluid shifts may still occur. In addition, technical factors, including selection of prediction equation, may be important when TBW is estimated from measured impedance.

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Bland and Altman plots between TBW estimated from the dilution technique and single-frequency mode (50 kHz) for (a) adult males and (b) boys.
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nutrients-06-01886-f002: Bland and Altman plots between TBW estimated from the dilution technique and single-frequency mode (50 kHz) for (a) adult males and (b) boys.

Mentions: The variability of TBW estimation using different frequency modes are shown in Table 4. Compared with the dilution technique, results from both MF and SF modes showed high correlation coefficients of 0.956 to 0.988. However, Bland and Altman plots for the supine position showed that TBW of almost all adult males was overestimated when the MF mode was used (Figure 1a) and calculated limits of agreement indicated an average of 2.4 L overestimation with a wide variability of about 3.7 L (Table 4). In comparison, boys showed relatively accurate estimation of TBW but some boys with a larger TBW were overestimated (Figure 1b). Calculated limits of agreement indicated that TBW estimation using the MF mode for boys had an underestimation of 0.38 L with variability of about 2 L. Similarly, TBW from the dilution technique and the SF mode using 50 kHz was compared. In males, the Bland and Altman plot indicated that individuals with relatively low TBW values (less than 40 L) were overestimated by the SF mode whereas the opposite was true for those with relatively high TBW (greater than 40 L). Limits of agreement indicated, on average, overestimated about 0.7 L with a variability of approximately 4 L. In boys, TBW was underestimated in all participants with potentially greater underestimation in individuals with a higher TBW (Figure 2). Limits of agreement showed about 2.7 L of underestimation with a variability of 2.4 L.


Influence of posture and frequency modes in total body water estimation using bioelectrical impedance spectroscopy in boys and adult males.

Kagawa M, Wishart C, Hills AP - Nutrients (2014)

Bland and Altman plots between TBW estimated from the dilution technique and single-frequency mode (50 kHz) for (a) adult males and (b) boys.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4042563&req=5

nutrients-06-01886-f002: Bland and Altman plots between TBW estimated from the dilution technique and single-frequency mode (50 kHz) for (a) adult males and (b) boys.
Mentions: The variability of TBW estimation using different frequency modes are shown in Table 4. Compared with the dilution technique, results from both MF and SF modes showed high correlation coefficients of 0.956 to 0.988. However, Bland and Altman plots for the supine position showed that TBW of almost all adult males was overestimated when the MF mode was used (Figure 1a) and calculated limits of agreement indicated an average of 2.4 L overestimation with a wide variability of about 3.7 L (Table 4). In comparison, boys showed relatively accurate estimation of TBW but some boys with a larger TBW were overestimated (Figure 1b). Calculated limits of agreement indicated that TBW estimation using the MF mode for boys had an underestimation of 0.38 L with variability of about 2 L. Similarly, TBW from the dilution technique and the SF mode using 50 kHz was compared. In males, the Bland and Altman plot indicated that individuals with relatively low TBW values (less than 40 L) were overestimated by the SF mode whereas the opposite was true for those with relatively high TBW (greater than 40 L). Limits of agreement indicated, on average, overestimated about 0.7 L with a variability of approximately 4 L. In boys, TBW was underestimated in all participants with potentially greater underestimation in individuals with a higher TBW (Figure 2). Limits of agreement showed about 2.7 L of underestimation with a variability of 2.4 L.

Bottom Line: While TBW estimated from the MF mode was comparable, extra-cellular fluid (ECF) and intra-cellular fluid (ICF) values differed significantly (p < 0.01) between the different postures in both groups.Measurement posture may not affect estimation of TBW in boys and adult males, however, body fluid shifts may still occur.In addition, technical factors, including selection of prediction equation, may be important when TBW is estimated from measured impedance.

View Article: PubMed Central - PubMed

Affiliation: Institute of Nutrition Sciences, Kagawa Nutrition University, Saitama 350-0288, Japan. mskagawa@eiyo.ac.jp.

ABSTRACT
The aim of the study was to examine differences in total body water (TBW) measured using single-frequency (SF) and multi-frequency (MF) modes of bioelectrical impedance spectroscopy (BIS) in children and adults measured in different postures using the deuterium (2H) dilution technique as the reference. Twenty-three boys and 26 adult males underwent assessment of TBW using the dilution technique and BIS measured in supine and standing positions using two frequencies of the SF mode (50 kHz and 100 kHz) and the MF mode. While TBW estimated from the MF mode was comparable, extra-cellular fluid (ECF) and intra-cellular fluid (ICF) values differed significantly (p < 0.01) between the different postures in both groups. In addition, while estimated TBW in adult males using the MF mode was significantly (p < 0.01) greater than the result from the dilution technique, TBW estimated using the SF mode and prediction equation was significantly (p < 0.01) lower in boys. Measurement posture may not affect estimation of TBW in boys and adult males, however, body fluid shifts may still occur. In addition, technical factors, including selection of prediction equation, may be important when TBW is estimated from measured impedance.

Show MeSH