Beddoe A H, Streat S J, Hill G L
Am J Physiol. 1985 Aug;249(2 Pt 1):E227-33. doi: 10.1152/ajpendo.1985.249.2.E227.
It is widely believed that increased hydration of the fat-free body accompanies most major disease processes as a result of contraction of the body cell mass and expansion of the extracellular fluid. Measurements of total body water (TBW) and total body nitrogen in 68 normal volunteers and 95 surgical ward patients presenting for intravenous nutrition have been used to derive ratios of TBW to fat-free mass (TBW:FFM) and protein indices (PI), where PI is defined as the ratio of measured total body protein to predicted TBP. Mean values of PI were 1.009 +/- 0.116 (SD) and 0.783 +/- 0.152 in the normal and patient groups, respectively, corresponding to mean TBW:FFM ratios of 0.719 +/- 0.016 and 0.741 +/- 0.029. However, 48 patients had normal TBW:FFM despite having lost 15% of body protein. A theoretical model of body composition changes in catabolic illness is presented, which is in accord with the patient data, demonstrating that TBW:FFM does not necessarily increase in catabolic illness and that the ratio masks underlying shifts in body fluid compartments.
人们普遍认为，由于体细胞群收缩和细胞外液扩张，大多数主要疾病过程都会伴随无脂身体的水合作用增加。对68名正常志愿者和95名接受静脉营养的外科病房患者进行了全身水（TBW）和全身氮测量，以得出TBW与无脂质量的比率（TBW:FFM）和蛋白质指数（PI），其中PI定义为测量的全身蛋白质与预测的全身蛋白质之比。正常组和患者组的PI平均值分别为1.009±0.116（标准差）和0.783±0.152，对应的平均TBW:FFM比率分别为0.719±0.016和0.741±0.029。然而，48名患者尽管身体蛋白质损失了15%，但其TBW:FFM仍正常。本文提出了一个分解代谢性疾病中身体成分变化的理论模型，该模型与患者数据相符，表明在分解代谢性疾病中TBW:FFM不一定会增加，且该比率掩盖了体液 compartments的潜在变化。
