Brundin T, Thörne A, Wahren J
Department of Clinical Physiology, Karolinska Hospital, Stockholm, Sweden.
Metabolism. 1992 Jan;41(1):49-55. doi: 10.1016/0026-0495(92)90190-l.
The mechanism behind the meal-induced increase in energy expenditure in humans and its reduction in obesity was examined in 15 normal-weight and seven obese subjects. The subjects were studied by indirect calorimetry in the basal state and during 2 hours after a mixed meal corresponding to 40% of the 24-hour basal energy requirement. Artificial thermal insulation was applied over the abdominal area before the study in seven of the normal-weight subjects. Thermistor catheters were inserted into a hepatic vein, the pulmonary artery, and a systemic artery for blood sampling and recording of blood temperatures. Basal hepatic venous drainage of heat in relation to the splanchnic oxygen uptake in the normal-weight subjects was low (12 +/- 1 J/mL O2) and became even lower after the meal (5 +/- 3 J/mL). In the obese individuals and the insulated subjects, blood-drained splanchnic heat amounted to 19 to 21 J/mL oxygen both before and after the meal. The postprandial increase in whole body energy expenditure was diminished both in the obese (12% +/- 1% above basal) and in the insulated subjects (15% +/- 1%) compared with the noninsulated controls (22% +/- 2%). In normal-weight subjects, there is a leakage of heat across the abdominal wall. Reduction or prevention of this leakage by artificial thermal insulation or by obesity is accompanied by a reduction of the postprandial increase in energy expenditure.
在15名体重正常的受试者和7名肥胖受试者中，研究了进食后人体能量消耗增加及其在肥胖状态下减少的机制。通过间接测热法对受试者在基础状态以及进食相当于24小时基础能量需求40%的混合餐后2小时内进行研究。在7名体重正常的受试者研究前，在腹部区域施加人工隔热。将热敏电阻导管插入肝静脉、肺动脉和体动脉，用于采血和记录血液温度。体重正常的受试者基础状态下肝脏静脉散热与内脏氧摄取量的比值较低（12±1焦耳/毫升氧气），进食后更低（5±3焦耳/毫升）。在肥胖个体和隔热受试者中，进食前后经血液排出的内脏热量均为19至21焦耳/毫升氧气。与未隔热的对照组（22%±2%）相比，肥胖受试者（比基础状态高12%±1%）和隔热受试者（15%±1%）餐后全身能量消耗的增加均减少。在体重正常的受试者中，存在热量通过腹壁泄漏的情况。通过人工隔热或肥胖减少或防止这种泄漏，会伴随着餐后能量消耗增加的减少。
