Pupim Lara B, Majchrzak Karen M, Flakoll Paul J, Ikizler T Alp
Department of Medicine, Division of Nephrology, Vanderbilt University Medical Center, Nashville, Tennessee 37232-2372, USA.
J Am Soc Nephrol. 2006 Nov;17(11):3149-57. doi: 10.1681/ASN.2006040413. Epub 2006 Oct 4.
Decreased dietary protein intake and hemodialysis (HD)-associated protein catabolism predispose chronic HD (CHD) patients to deranged nutritional status, which is associated with poor clinical outcome in this population. Intradialytic parenteral nutrition (IDPN) reverses the net negative whole-body and skeletal muscle protein balance during HD. IDPN is costly and restricted by Medicare and other payers. Oral supplementation (PO) is a more promising, physiologic, and affordable intervention in CHD patients. Protein turnover studies were performed by primed-constant infusion of L-(1-(13)C) leucine and L-(ring-(2)H(5)) phenylalanine in eight CHD patients with deranged nutritional status before, during, and after HD on three separate occasions: (1) with IDPN infusion, (2) with PO administration, and (3) with no intervention (control). Results showed highly positive whole-body net balance during HD for both IDPN and PO (4.43 +/- 0.7 and 5.71 +/- 1.2 mg/kg fat-free mass per min, respectively), compared with a neutral balance with control (0.25 +/- 0.5 mg/kg fat-free mass per min; P = 0.002 and <0.001 for IDPN versus control and PO versus control, respectively). Skeletal muscle protein homeostasis during HD also improved with both IDPN and PO (50 +/- 19 and 42 +/- 17 microg/100 ml per min) versus control (-27 +/- 13 microg/100 ml per min; P = 0.005 and 0.009 for IDPN versus control and PO versus control, respectively). PO resulted in persistent anabolic benefits in the post-HD phase for muscle protein metabolism, when anabolic benefits of IDPN dissipated (-53 +/- 25 microg/100 ml per min for control, 47 +/- 41 microg/100 ml per min for PO [P = 0.039 versus control], and -53 +/- 24 microg/100 ml per min for IDPN [P = 1.000 versus control and 0.039 versus PO]). Long-term studies using intradialytic oral supplementation are needed for CHD patients with deranged nutritional status.
饮食蛋白质摄入量减少和血液透析(HD)相关的蛋白质分解代谢使慢性HD(CHD)患者易出现营养状况紊乱,而这种紊乱与该人群不良的临床结局相关。透析期间胃肠外营养(IDPN)可扭转HD期间全身和骨骼肌蛋白质的净负平衡。IDPN成本高昂,且受到医疗保险和其他付款方的限制。口服补充营养(PO)对CHD患者而言是一种更具前景、符合生理且经济实惠的干预措施。通过对8名营养状况紊乱的CHD患者在HD前、HD期间和HD后三个不同阶段进行L-(1-(13)C)亮氨酸和L-(环-(2)H(5))苯丙氨酸的首剂-持续输注来进行蛋白质周转研究:(1)输注IDPN,(2)给予PO,(3)不进行干预(对照)。结果显示,与对照时的中性平衡(每分钟每千克去脂体重0.25±0.5毫克)相比,HD期间IDPN和PO的全身净平衡均为高度正值(分别为每分钟每千克去脂体重4.43±0.7和5.71±1.2毫克;IDPN与对照相比P = 0.002,PO与对照相比P<0.001)。HD期间,IDPN和PO均使骨骼肌蛋白质稳态得到改善(分别为每分钟50±19和42±17微克/100毫升),而对照时为负值(每分钟-27±13微克/100毫升;IDPN与对照相比P = 0.005,PO与对照相比P = 0.009)。当IDPN的合成代谢益处消失后,PO在HD后阶段对肌肉蛋白质代谢产生了持续的合成代谢益处(对照为每分钟-53±25微克/100毫升,PO为每分钟47±41微克/100毫升[与对照相比P = 0.039],IDPN为每分钟-53±24微克/100毫升[与对照相比P = 1.000,与PO相比P = 0.039])。对于营养状况紊乱的CHD患者,需要进行使用透析期间口服补充营养的长期研究。