The effects of skin temperature on bioelectric impedance measurement for body composition assessment

• Main Authors: Huey-Fen Su, 蘇蕙芬
• Other Authors: Ning-Yuean Lee ; Michael T.C. Liang
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/61380431597793277958

碩士 === 國立體育學院 === 運動科學研究所 === 82 === To examine the effects of skin temperature (Tsk) on bio- electric impedance analysis（BIA）of resistance（R）and reactance Xc ）, and BIA prediction equation. Twenty young females, with age ( mean±SD ): 19.7 ±0.9 Yr, height: 160.1 ± 6.2 cm, weight: 56.8 ± 9.3 Kg, volunteered as subjects. All subjects underwent skin temperature and BIA measuremeants under three temperature conditions: 1) 24.9 ℃ (nomal,N), 2) 17.3 ℃, (cold, C), and 3) 35.3 ℃ (hot, H). The measured R and Xc values were used to compute fat-free mass (FFM) according to the equations of Lukaski (1987) and Guo (1989). The estimated FFM values were compared with the underwater weighing method (UW). Data was tested by repeated measurements of one-way ANOVA. If the result was significant Tukey post-hoc test was used. Results of this study shows that: 1)the mean Tsk and the four measured sites ( calf, thigh, bicept, and chest ) were significantly decreased from N to C and increased from N to H; 2) the BIA measured R values were significantly increased from N to C ( △ 25 Ω ) and decreased from N to H ( △ 20 Ω ). The Xc values were significantly increased from N to C ( △ 6 Ω ) and decreased from C to H ( △ 7 Ω ); 3) the FFM computed by two BIA prediction equations were significantly decreased from N to C and increased from N to H; 4) the Lukaski prediction equation significantly underestimated FFM by 1.2 Kg; and 5) the Guo rediction lquation significantly underestimated FFM by 3.0 Kg. We conclude that 1) varying skin temperature by altering ambient temperture significantly changed the BIA measurement of R and Xc; and 2) varying skin temperture significantly affected the FFM determination. Thus, we recommend that BIA measurement should be taken under standardized ambient conditions, to avoid the effect of skin temperature. We observed that both Lukaski(1987) and Guo(1989) equations underestimated FFM of young Chinese female.