Kurpad A V, Borgonha S, Shetty P S
Department of Physiology, St. John's National Academy of Health Sciences, Bangalore.
Indian J Med Res. 1997 May;105:212-9.
Doubly labelled (2H2(18)O) water was used to determine the daily total energy expenditure (TEE) in the free living state of 6 adult, healthy, weight stable, male volunteers over a period of 21 days. The body weights of the subjects ranged from 42.3-70.4 kg. Isotope pool sizes and elimination rates were calculated from 18O and 2H enrichments in basal and daily (21 days) post dose urine samples using the multipoint slope intercept method after corrections for isotope fractionation. The physical activity level (PAL) of the subjects was also measured during the experiment as the ratio of measured TEE to measured basal metabolic rate (BMR). Simultaneous prediction of the total energy expenditure was also carried out by combining the measurements of BMR by indirect calorimetry, and daily physical activity level by 7 day recall. TEE calculated by the isotopic technique was 9.35 +/- 2.00 MJ/day, with an inter individual variation of 21.4 per cent. The measured BMRs in the subjects along with PALs obtained by recall, gave a total daily energy expenditure of 8.66 +/- 2.20 MJ/day with an inter individual variation of 25.4 per cent. The average BMR was 5.59 +/- 0.99 MJ/day and the average PAL (by recall) was 1.54 +/- 0.12. The inter individual variation of the BMR was 17.7 per cent and that of the recalled PAL was 7.9 per cent; the latter increased to 12.2 per cent when the PAL was calculated from the ratio of the measured TEE to the BMR. There was no significant differences between the methods (isotopic and predicted by BMR), although, the TEE obtained by the isotopic method was higher, by about 0.7 MJ/day, or 7.9 per cent, than the TEE predicted by BMR.
使用双标记（2H2(18)O）水来测定6名成年、健康、体重稳定的男性志愿者在21天自由生活状态下的每日总能量消耗（TEE）。受试者的体重范围为42.3 - 70.4千克。在对同位素分馏进行校正后，使用多点斜率截距法根据基础和每日（21天）给药后尿液样本中的18O和2H富集度计算同位素池大小和消除率。在实验过程中，还测量了受试者的身体活动水平（PAL），即测量的TEE与测量的基础代谢率（BMR）的比值。还通过结合间接测热法测量的BMR和7天回顾法测量的每日身体活动水平，对总能量消耗进行了同时预测。通过同位素技术计算的TEE为9.35±2.00兆焦/天，个体间差异为21.4%。受试者测量的BMR以及通过回顾获得的PAL得出每日总能量消耗为8.66±2.20兆焦/天，个体间差异为25.4%。平均BMR为5.59±0.99兆焦/天，平均PAL（通过回顾）为1.54±0.12。BMR的个体间差异为17.7%，回顾的PAL的个体间差异为7.9%；当根据测量的TEE与BMR的比值计算PAL时，后者增加到12.2%。尽管同位素方法获得的TEE比BMR预测的TEE高约0.7兆焦/天，即高7.9%，但两种方法（同位素法和BMR预测法）之间没有显著差异。
