增强体质,扭转肌肉衰减——老年肌少症应口服营养补充剂

老年人体质虚弱的一个重要表现,是肌肉衰减和与之相关联的免疫力降低。老年肌少症,就是指老年人随增龄出现的进行性骨骼肌质量减少,伴有肌肉力量或肌肉功能的减退。营养素的缺乏及其导致的肌蛋白合成降低,是肌少症发生和进展的重要原因。     

外科创伤与术后营养支持:肌肉蛋白质代谢的纵向研究

外科创伤后机体处在分解代谢状态,其中包括体重下降,肌肉萎缩,尿氮丢失量增加;同时伴有肌肉蛋白质合成减少以及大量的氨基酸由肌肉流向内脏器官,最终导致肌肉中的游离氨基酸其中主是谷氨酰胺(GLN)水平下降和肌肉功能减退,这些后果是常规的肠外营养所无法预防的.然而,补充谷氨酰胺的肠外营养可改善外科术后早期氮平衡,预防肌肉蛋白质合成下降及肌肉中游离的谷氨酰胺减少.     

腹腔感染后肌肉蛋白质代谢改变的实验研究

目的：进一步观察感染后骨骼肌蛋白质代谢的变化。方法：大量为实验对象,分为正常对照,正常加TPN和感染加TPN三组。观察感染后肌肉蛋白、谷氨酰胺含量和尿3－甲基组氨酸排泄量的变化,以及肌肉中泛素和肌纤蛋白基因表达的变化。结果：感染后尿3－甲组氨酸排出量明显增加,同时肌肉蛋白及谷氨酰胺含量明显下降。感染后肌肉肌纤维蛋白基因表达下降,而肌肉泛素蛋白基因表达显著增强。结论：感染后肌肉蛋白分离增加,并且此时蛋白合成明显受抑制。     

重组人生长激素和口服谷氨酰胺双肽联合应用改善严重烧伤患者内毒素血症的作用

目的探讨重组人生长激素(rhGH)和口服谷氨酰胺双肽(Glutaminedipeptide)改善严重烧伤病人内毒素血症的作用。方法36例烧伤总面积大于40%,Ⅲ度面积大于20%的患者加入研究,随机分为对照组(Controlgroup),谷氨酰胺双肽组(GLNgroup)和联合应用谷氨酰胺双肽及重组人生长激素组(GLN+rhGHgroup)。每组12人,对照组常规治疗;谷氨酰胺双肽组伤后1～14天口服谷氨酰胺双肽0.5g     

蛋白质代谢的营养指标—3-甲基组氨酸

3-甲基组氨酸(3-MEH)是组氨酸通过蛋白质合成甲基化后生成的氨基酸。在体内存在于骨骼肌蛋白的肌纤蛋白和肌球蛋白中,在肌蛋白分解过程中释放经过氧化放出能量,其原形从尿中排出。通常认为肌蛋白含有一定比例的3MEH。根据Young等的研究,尿中排泄3MEH 4.2μmol相当干分解1g肌蛋白,所以测定尿中3-MEH的排泄量,按一定的系数可以推算出肌蛋白的分解量。此外, 肌酸酐的尿中排泄量同肌肉量有一定的比例,所以,求出3MEH和肌(?)酐的比也能知道每单位肌肉肌蛋白的分解速度。     

围手术期谷氨酰胺强化全肠外营养对胃肠道肿瘤病人营养状况的影响

目的:研究围手术期谷氨酰胺强化的全肠外营养(TPN)对接受术前化疗的胃肠道肿瘤病人营养状况的影响. 方法:将60例胃肠道肿瘤病人随机分为TPN组、谷氨酰胺强化TPN (Gln-TPN)组和对照组,每组20例病人.对照组给予常规术前准备和术后治疗,TPN组和Gln-TPN组分别给予术前5 d和术后5 d营养支持.两组给予等氮0.20 g/(kg·d)和等热量104.6 kJ/(kg·d),同时接受为期5 d的术前化疗.Gln-TPN组中25%～35%的氮源由谷氨酰胺双肽提供,其余的氮源及TPN组的氮源由乐凡命提供.检测术前、术后病人的体重、肱三头肌皮皱厚度、上臂肌围、血浆清蛋白、前清蛋白、转铁蛋白、血浆和肌肉中谷氨酰胺浓度、氮平衡等营养指标.结果:研究期间三组病人无严重并发症发生.三组病人术后体重、肱三头肌皮皱厚度、上臂肌围,血浆前清蛋白、转铁蛋白浓度、氮平衡,均较术前明显下降,术后三组间比较差异无显著性意义.对照组体重丢失最为严重,术后第6 d Gln-TPN组肌肉中及血浆谷氨酰胺浓度明显高于其他两组.结论:谷氨酰胺强化的TPN可提高血浆和肌肉中谷氨酰胺浓度,减少肌肉分解、脂肪消耗,促进机体蛋白质的合成,有益于减轻手术和化疗造成的高分解状态.     

创伤及感染时GH-IGF-IGFBP轴的变化及其临床意义

创伤和感染病人往往存在高分解代谢,包括蛋白质合成减少、分解增加,形成明显的负氮平衡.如何逆转高分解反应曾经过漫长的探索.除了营养支持外,人们希望通过抗分解激素减轻甚至是逆转高分解状态.新近研究提示,在基础和应激条件下,生长激素-胰岛素样生长因子-胰岛素样生长因子结合蛋白(GH-IGF-IGFBP)轴对调节肌肉蛋白质代谢起着核心作用.该文作者就其在创伤及感染时的变化及其临床意义作一综述.     

生长抑素／生长激素释放激素-生长激素-胰岛素样生长因子-1轴与营养

介绍近几年来生长抑素／生长激素释放激素-生长激素-胰岛素样生长因子轴营养调节的研究进展，包括营养不良时生长激素，胰岛素样生长因子-1的变化，生长激素抵抗，生长激素受体与受体后缺陷，生长激素受体后缺陷的分子机制及胰岛素样生长因子-1的清除与降解。简单阐述了生长激素，胰岛素样生长因子-1对分解代谢，神经肌肉疾病，骨质疏松，肾功能不全，肥胖，老年人营养不良，生长激素缺乏及生长激素受体或受体后缺陷综合征的影响及治疗意义。     

术前肌肉减少症对胃癌病人临床预后的影响:一项前瞻性队列研究

目的:探讨胃癌病人术前存在肌肉减少症对术后病人临床预后的影响。方法:前瞻性纳入93例胃癌病人,使用生物电阻抗法检测骨骼肌质量,分为两组:肌肉减少症组和非肌肉减少症组,比较分析术前存在肌肉减少症对胃癌病人术后总并发症发生率、住院时间、住院费用、60天再入院及病死率等指标的影响。结果:术前存在肌肉减少症的病人与正常对照组相比:总并发症发生率、总住院天数和术后住院天数具有显著性差异(P0.05)。60天再入院率、60天病死率和总住院费用方面肌肉减少症组略高于正常对照组,但无统计学差异(P0.05)。单因素和多因素分析显示,术前存在肌肉减少症及存在营养风险是增加术后并发症发生率的独立危险因素。结论:术前存在肌肉减少症可导致胃癌病人术后不良临床预后,肌肉减少症是胃癌病人术后并发症增加的独立危险因素,术前应常规进行筛查与评估并及时纠正。     

GH对创伤与感染SD大鼠IGF-1水平及营养代谢的影响

目的　探讨创伤与感染及外源性生长激素对SD雄性大鼠血清胰岛素样生长因子-1(IGF-1)及营养代谢的影响。　方法　SD雄性大鼠60只，随机分成生长激素治疗组和对照组(各30只)，复制成腹腔感染动物模型，治疗组术后第1天开始给予GH0.5U     

Combination of recombinant human growth hormone and glutamine-enriched total parenteral nutrition to surgical patients: effects on circulating amino acids

BACKGROUND & AIMS: Both recombinant human growth hormone (rhGH) and glutamine (GLN) may have beneficial anabolic actions on amino acid metabolism. The aim of this study was to evaluate the additive effects of rhGH and GLN on plasma amino acids postoperatively. METHODS: 31 females undergoing laparoscopic cholecystectomy were randomized to three groups: Group I (n=10) received 13 IU/m(2) of rhGH the morning of surgery and the following three postoperative days, together with glutamine-free TPN for the first two postoperative days. Group II (n=11) received rhGH as the first group, together with glutamine-enriched (7 g GLN/m(2)/day) TPN. Group III (n=10) received glutamine-enriched TPN as the second group, but rhGH was replaced by placebo. Daily plasma amino acid concentrations and nitrogen balance were determined. RESULTS: In the GH treated groups, the plasma concentrations of several amino acids were decreased on the third postoperative day, compared to preoperatively. This was not observed in Group III. The changes were more pronounced in Group II. In Group II the negative AV-differences of amino acids tended to be attenuated, while the patients in Group III had increased negative AV-differences. The cumulative nitrogen balance was significantly improved in the GH groups, compared with Group III. CONCLUSION: The combined treatment of growth hormone and glutamine has additive effects on AV-balances of amino acids postoperatively, whereas nitrogen balance is not further improved when adding glutamine to rhGH treatment.     

Growth hormone pre-treatment combined with exogenous glutamine induced a postoperative shift from glucose to glutamine consumption in the gastrointestinal tract

The aim of this study was to assess whether the protein sparing effects associated with administration of growth hormone (GH) and glutamine in the early post traumatic period deprive the gastrointestinal tract of substrates. Sixteen piglets were randomized to receive GH treatment (n = 8) for 3 days prior to surgery whilst a control group (n = 8) received no growth hormone. Organ fluxes of glucose, lactate, pyruvate, alanine and glutamine were measured at 1 and 5 h after surgery. An infusion of glutamine (36 microg/kg/min) was started after the first measurement in both groups. In the GH group (5 h after surgery), hindleg release of glutamine and alanine was found to be lower than in the control group, whilst intestinal glutamine uptake was higher and that of alanine was lower. Hepatic alanine uptake was reduced whilst hepatic glutamine exchange switched from uptake to release. Intestinal glucose consumption was lower in the GH group (P < 0.05). It is concluded that GH pre-treatment in combination with exogenous glutamine administration induced a shift in gastrointestinal fuel selection which was associated with reduced glucose consumption and increased glutamine consumption. The effect of GH in inducing hepatic release of glutamine compensated for its effect on muscle which results in reduced peripheral glutamine release.     

丙氨酰胺谷氨酰胺对术后化疗消化道肿瘤患者的作用

目的研究添加丙氨酰胺谷氨酰胺(Ala-Gln)的全胃肠外营养(TPN)对术后化疗消化道肿瘤患者的作用。方法30例消化道肿瘤患者,按序随机分为两组传统组和二肽组,每组15例,术后给予等热量(104.6kJ     

重组人生长激素对慢性腹腔感染病人蛋白质代谢的影响

目的：研究重组人生长激素对促进慢性腹腔感染病人蛋白质代谢的影响。方法：20例慢性腹腔感染病人随机分为GH组（TPN GH）和对照组（TPN）,研究时间为10天。分别于研究前与研究结束时进行感染评分,检测血清生长激素（GH）、血清胰岛素样生长因子-1（IGF-1）、血清胰岛素样生长因子结合蛋白-3（IGFBP-3）;分别于研究前、研究第3天、第7天及研究结束时,检测血清白蛋白、前白蛋白转铁蛋白、纤维连接蛋白、C-反应蛋白;测定每天氮平衡及24h尿肌酐。结果：研究结束时GH组GH、IGF-1、IGFBP-3显著高于对照组及研究前;研究期间GH组血清白蛋白、前白蛋白、转铁蛋白、纤维连接蛋白升高,而C-反应蛋白下降;氮平衡改善,累计氮平衡显著高于对照组,而24h尿肌酐则下降。结论：重组人生长激素能促进慢性腹腔感染病人蛋白质代谢,而IGF-1在其中发挥了重要作用。     

Nitrogen sparing effect of Ornicetil in the immediate postoperative state clinical biochemistry and nitrogen balance

The salt complex of alpha-ketoglutarate and ornithine, L(+)ornithine alpha-ketoglutarate - ORNICETIL (OR) - is able to bind six amino groups per molecule without enzymatic intervention. The present study was undertaken to determine whether intravenous administration of OR together with total parenteral nutrition (TPN) has a beneficial effect on nitrogen utilization in the immediate postoperative phase. Thirteen patients were investigated after major abdominal operations (resection of colon or rectum). All patients received TPN for 5 days postoperatively. Energy (165 kJ/kg BW) was given as fat (Intralipid 20%) and carbohydrate (Glucose 20%). Seven patients (controls) received 0.15 g amino acid (AA)-N/kg BW (Vamin). Six patients had an isonitrogenous regimen but with 2.5 g AA-N being replaced by Ornicetil (OR group). The excretion of urea, creatinine, ammonia, 3-methyl-histidine (3-MeHis) and total-N was determined throughout the study and the daily nitrogen balance was calculated. Blood samples were drawn serially before and after surgery for routine clinical biochemistry. The day-to-day nitrogen balance was significantly better when OR was given. Urea excretion was significantly reduced, and the urinary ammonia losses in the OR group were one third of those in the control group. In the control group 3-MeHis correlated negatively with the nitrogen balance. The regression line obtained, y = 265 - 21.6 x (p < 001), and the calculated correlation coefficient, r = 0.87 (p < 0.001), were highly significant. In contrast, no correlation could be demonstrated between 3-MeHis output and nitrogen balance in the OR group (r = 0.18, N.S.). The results indicate better postoperative nitrogen economy in the OR group than in the control group. Stimulation of insulin and growth hormone secretion may be contributing factors in the better nitrogen utilization. The increased ammonia excretion postoperatively in the control group was completely abolished when OR was given simultaneously with decreased urea formation, suggesting a product inhibition of arginase in the liver cytosol and also indicating that amino groups generated by the enhanced gluconeogenesis were trapped by OR owing to stimulated transamination in peripheral muscle tissues. The significant negative correlation between 3-MeHis excretion and nitrogen balance in the control group strongly indicates a correlation between net protein catabolism and increased postoperative muscle protein breakdown. In contrast, the total absence of correlation between nitrogen balance and 3-MeHis excretion in the OR group suggests a diminished (or zero) net muscle protein breakdown.     

重组人生长激素对消化道术后病人氮平衡作用的研究

目的了解重组人生长激素(rhGH)对手术后病人氮平衡的影响。方法在肠全外营养(TIN)的基础上，加用rhGH治疗消化道大中型手术后10例病人，并与同期仅用TPN治疗的10例病人做对照研究。结果1．2组病人均未获得正氮平衡，但GH组氮平衡明显改善；术后5天累积氮平衡GH组显高于对照组。2．术后3天、5天，累积尿氮的排出，对照组较GH组高，二差别有显统计学意义。3．术后1天引流氮的排出、术后3天累积引流氮的排出及平均每天引流氮的排出，GH组均较对照组低，但无显的统计学意义。结论在低氮和低热的基础上，rhGH能减轻术后病人的负氮平衡。主要是通过减少尿氮的排出而达到节氮效果，rhGH对引流氮影响不大。     

丙氨酰胺谷氨酰胺对烫伤大鼠的作用

目的研究添加丙氨酰谷氨酰胺(Ala-Gln)全胃肠外营养对烫伤大鼠的蛋白质代谢、肠粘膜形态学、创面肉芽组织的影响。方法将22只30%TBSAⅢ度烫伤SD大鼠行颈外静脉插管后,随机分为传统TPN组(传统组)和添加二肽TPN组(二伏组),每组各11例,两组接受等热量(780kg     

Protein dynamics during refeeding of protein-depleted rats: effects of increasing amino acid intake by TPN or enteral continuous feeding

The effect of increasing nitrogen intake with constant calorie supply was studied in protein-depleted rats. Animals were randomized into three paired groups to receive either total parenteral nutrition (TPN) or enteral (EF) isocaloric feedings (240 kcal X kg-1 X day-1) differing only in their amount of amino acids. The diets, composed of dextrose, a safflower oil emulsion and crystalline amino acids, were infused continuously for 5 days. Daily nitrogen intakes were for controls (EF, n = 7; TPN, n = 6) 0.25 g/kg; for groups 1 (EF, n = 7; TPN, n = 8) 1.4 g/kg and for groups 2 (EF, n = 7; TPN, n = 7) 2.5 g/kg. The rats in groups 1 and 2 obtained significant protein repletion in terms of body weight, nitrogen retention, liver protein and serum albumin regardless of the route of nutrient delivery. However, rats in groups 2 (higher nitrogen intake) presented a more rapid and greater recovery despite a reduction in nitrogen utilization. Whole-body leucine kinetics studied at the end of controlled feeding periods were similar for EF and TPN rats. However, increasing nitrogen intake (1 and 2) increased whole-body leucine flux and incorporation into protein resulting in a better balance, since leucine release from protein breakdown was comparable to controls. Liver protein fractional synthetic rates were reduced in EF while remaining at a high rate in TPN group 2 and still more elevated in TPN group 1, suggesting a preferential support of liver protein by enteral feeding or the effect of TPN as a non-physiologic route.     

Effects of glutamine-enriched total parenteral nutrition on acute pancreatitis

AIM: This study was performed to determine the effects of glutamine enriched total parenteral nutrition (TPN) on the patients with acute pancreatitis (AP). METHOD: Forty patients with AP, who had Ranson's score between 2 and 4 received either standard TPN (control group) or TPN with glutamine (treatment group). The patients in the treatment group received TPN containing 0.3 g/kg/days glutamine. At the end of the study, patients were evaluated for nutritional and inflammatory parameters, length of TPN and length of hospital stay. RESULTS: The length of TPN applications were 10.5+/-3.6 days and 11.6+/-2.5 days, and the length of hospital stays were 14.2+/-4.4 and 16.4+/-3.9 days for the treatment and control groups (NS), and the complication rates in the treatment and control groups were 10 and 40%, respectively (P<0.05). The transferrin level increased by 11.7% in the group that received glutamine-enriched TPN (P<0.05), whereas the transferrin level decreased by 12.1% in the control group (NS). At the end of the study, slight but not significant changes were determined in both groups in fasting blood sugar, albumin, blood urea nitrogen (BUN), creatinine, total cholesterol concentrations, aspartate aminotransferase (AST), alanine transaminase (ALT) and lactate dehydrogenase (LDH) activities, leukocytes, CD(4), CD(8), serum Zn, Ca and P levels compare to the baseline levels (NS). Significant decreases were determined in serum lipase, amylase activities and C-reactive protein (CRP) levels in both groups (P<0.05). CONCLUSIONS: The results of this study have shown that glutamine supplementation to TPN have beneficial effects on the prevention of complications in patients with AP.