Powell-Tuck J
Gut. 1986 Nov;27 Suppl 1(Suppl 1):67-71. doi: 10.1136/gut.27.suppl_1.67.
Major loss of body protein mass in inflammatory bowel disease is much less common than weight loss, which is often attributable to losses of other body, particularly water and fat. It does occur, however, in a few patients, especially in those with compromised food intake. It is due principally to the combined effects of diminished intake and excessive intestinal losses of amino nitrogen. Nitrogen metabolism is influenced not only by protein nutritional state and net nitrogen intake but also by disease activity. There is some evidence for abnormally low secretion of growth hormone in adolescents with inflammatory bowel disease and growth failure. Low serum albumin concentrations are not necessarily related to protein undernutrition and are the combined result of relatively reduced albumin synthesis, increased intestinal losses, and maldistribution between intravascular and extravascular spaces. Concentrations in the plasma of IgG and acute phase reactants may be raised despite increased losses into the bowel lumen. The prevention of total body protein depletion is achieved principally by maintaining adequate and often not supranormal intakes of a balanced source of amino nitrogen in a balanced diet given orally, enterally, or parenterally, combined with a medical or surgical approach to reduce disease activity: supranormal energy intakes are not beneficial.
炎症性肠病中身体蛋白质大量流失的情况比体重减轻少见得多，体重减轻往往归因于身体其他成分的流失，尤其是水分和脂肪。然而，在少数患者中确实会出现蛋白质大量流失的情况，特别是那些食物摄入量受限的患者。这主要是由于氨基酸氮摄入量减少和肠道过度流失共同作用的结果。氮代谢不仅受蛋白质营养状态和净氮摄入量的影响，还受疾病活动的影响。有证据表明，患有炎症性肠病且生长发育迟缓的青少年生长激素分泌异常低。血清白蛋白浓度低不一定与蛋白质营养不良有关，而是白蛋白合成相对减少、肠道流失增加以及血管内和血管外空间分布不均共同作用的结果。尽管进入肠腔的损失增加，但血浆中IgG和急性期反应物的浓度可能会升高。预防全身蛋白质消耗主要通过在口服、肠内或肠外给予平衡饮食中保持足够且通常不超过正常量的平衡氨基酸氮来源摄入，同时结合医学或手术方法来降低疾病活动：摄入超过正常量的能量并无益处。
