Modifications of circadian cortisol rhythm by cyclic and continuous total enteral nutrition

To clarify the relationship between the pattern of diet intake and the circadian adrenocortical rhythm, we measured plasma cortisol levels at 4-h intervals over a 24-h period in 18 patients who were in the vegetative state and had been receiving total enteral nutrition (TEN) for 4 weeks. One group of 6 patients was given a liquid diet intraduodenally and continuously throughout a day (continuous TEN), whereas the two other groups received their daily enteral feeding during a restricted time of day, either in the daytime from 0800 h to 2000 h (diurnal TEN, 6 patients) or in the nighttime from 2000 h to 0800 h (nocturnal TEN, 6 patients). In patients with diurnal TEN, there was a clear cortisol rhythm with a peak of 0800 h, whose pattern was quite similar to the well-established cortisol rhythm in normal subjects. Patients with nocturnal TEN also showed a cortisol rhythm, but the peak appeared at 1600 h. There was no appreciable difference in the amplitude of the rhythm between the two groups. Patients with continuous TEN did not show any consistent circadian cortisol rhythms. Plasma levels of glucose, insulin, and free fatty acids also showed circadian fluctuations corresponding to the pattern of diet infusion in the groups with diurnal and nocturnal TEN, and remained almost constant throughout a day in the group with continuous TEN. We conclude from these results that the timing of diet intake may have a synchronizing effect on the circadian cortisol rhythm in man, as it does in laboratory animals.     

Effects of cyclic and continuous total enteral nutrition on 24-h rhythms of body temperature and urinary excretions.

To clarify the relationship between the pattern of diet intake and circadian rhythm in man, we measured body temperature and urinary excretions at 4-h intervals over a 24-h period in 18 patients who were in vegetative states and had been receiving total enteral nutrition (TEN) for at least 4 weeks. One group of patients was given a liquid diet intraduodenally and continuously throughout a day (continuous TEN), whereas the two other groups received their daily enteral feeding during a restricted time of day, either in the daytime from 0800 h to 2000 h (diurnal TEN) or in the nighttime from 2000 h to 0800 h (nocturnal TEN). In the diurnal TEN group, there was a clear body temperature rhythm with a peak at 2000 h, whose pattern was similar to the well-established body temperature rhythm in normal subjects. The nocturnal TEN group also showed a temperature rhythm, but the peak appeared at 0400 h. The continuous TEN group did not show any consistent body temperature rhythms. These effects of the schedule of TEN were quite similar to those on the circadian cortisol rhythm reported previously (J. Nutr. Sci. Vitaminol., 35, 639-647, 1989). In contrast to the body temperature rhythm, the rhythm of urinary excretions of water, sodium and potassium was little influenced by the schedule of TEN, showing a normal pattern with more excretions during the daytime in every group. Essentially the same effects were confirmed in a patient who received the three schedules of TEN in rotation for 5 weeks of each schedule.(ABSTRACT TRUNCATED AT 250 WORDS)     

Plasma amino acids in total parenteral nutrition comparison of continuous and cyclic parenteral nutrition

Cyclic nocturnal total parenteral nutrition (TPN) is a widely used technique but its metabolic consequences have not been fully investigated. The aim of this work was to investigate the influence of infusion rhythm on the plasma amino-acid profile in 12 subjects. During two successive 7-day periods and in a randomly chosen order, they received either standard continuous TPN (TPN_Co), i.e., 24 h a day or cyclic TPN (TPN_Cy), i.e., between 5 p.m. and 9 a.m. Caloric and nitrogen supplies were identical in both periods. Plasma amino-acids were analysed at 8:30 a.m. and 4:30 p.m. on the last day of each infusion period. In contrast to the stability observed in TPN_Co, TPN_Cy led to considerable variations of plasma amino-acid concentrations, creating a profile close to that observed in normal oral feeding conditions. Total 24 h urinary amino-acid elimination and the nitrogen balance did not differ between the two types of TPN. These results show that TPN_Cy induces a metabolic profile close to physiological conditions.     

Calciuretic effect of cyclic versus continuous total parenteral nutrition

Metabolic bone disease has been reported in patients receiving long-term cyclic administration of total parenteral nutrition (TPN). The exact etiology of this disturbance in mineral homeostasis has not been identified, however many of these patients are markedly hypercalciuric and in negative calcium balance. We have studied the effects of cyclical versus continuous infusion of nutrients on urinary calcium losses in a group of patients beginning a program of long-term home TPN. Cyclic TPN, when administered over either 18 or 12 hours, significantly increased daily urinary calcium excretion compared to continuous 24-h TPN infusion by 19 and 28%, respectively. During cyclic TPN, frank negative calcium balance was observed in 3 of 5 patients studied compared to 2 of 5 patients during continuous TPN. The pattern of urinary calcium loss during cyclic TPN was such that approximately 80% of the daily urinary calcium losses occurred during the 12 hours of TPN infusion. Cyclic administration of TPN increased the urinary calcium losses in all patients suggesting that an intermittent TPN infusion schedule, as typically utilized in home TPN programs, increases the risk of developing negative calcium balance, at least during the early phase of cyclic TPN administration.     

Effects of prolonged, purine-free total parenteral and enteral nutrition on urate homeostasis in man

The influence on human urate homeostasis of prolonged, totally purine-free nutritional support, using total parenteral (TPN) or elemental enteral (EN) nutrition, is not well known. In a prospective study, we measured weekly serum uric acid, renal urate excretion and clearance, together with parameters of hydration, in 58 normally hydrated patients receiving prolonged (15 to 170 days) purine-free TPN (30 patients) or EN (28 patients) for various gastrointestinal disorders. A marked, early and sustained decrease (p less than 0.001) in serum uric acid was observed in TPN (155 +/- 9 mumol/l at day 7 versus 318 +/- 13 mumol/l before nutrition, mean +/- SEM) as well as in EN patients (192 +/- 11 mumol/l at day 7 versus 320 +/- 16 mumol/l before nutrition), together with a significant (p less than 0.01) rise in renal urate clearance. The urate clearance/glomerular filtration rate ratio increased significantly, while there was no significant change in natremia or plasma osmolarity. Serum urate and urate clearance returned to normal within 8 days of refeeding with a normally purine-containing diet. Replacement of TPN by EN or vice versa, or substitution of glucose by fructose resulted in no change in hypouricemia. A 4-day oral supply of purines (125 mg/day) in EN patients was associated with a 53% rise (p less than 0.01) in serum urate. We conclude that prolonged, purine-free TPN and elemental EN are a new cause of marked hypouricemia which is mainly due to increased urate clearance, the mechanism of the latter is still poorly known, but is not related to extracellular volume expansion.     

肠外与肠内营养对胰腺外分泌和急性重症胰腺炎的影响

肠外营养(PN)不能改变胰腺炎自然病程,能降低并发症和病死率,但导管感染和肠源性并发症增加。近年来,肠内营养（EN）应用受到重视,但在急性重症胰腺炎（SAP）中的应用仍有争议。从EN对胰腺外分泌和SAP自然病程的影响分析,提出经空肠喂养不会刺激胰腺分泌,也不会加重SAP的病情。在临床实际应用中,应结合SAP的分期和临床状况,采用PN和EN联合应用来达到营养支持的目的。     

Comparison of the effects of continuous and cyclic nocturnal parenteral nutrition on energy expenditure and protein metabolism

Although cyclic nocturnal total parenteral nutrition is a widely used technique, its metabolic consequences have not been fully investigated. During two successive 7-day periods, 12 patients received randomly either standard continuous (infusion 24 hr/day) or cyclic (infusion between 5 pm and 9 am) total parenteral nutrition (TPN). Calorie and nitrogen intakes were identical during both periods. Energy expenditure was investigated by indirect calorimetry and showed practically no difference between continuous standard (1383 +/- 41 kcal/day-1) and cyclic total parenteral nutrition (1428 +/- 46 kcal/day-1). However, in the cyclic regimen, when compared with continuous infusion, energy expenditure was higher between 5 pm and 9 am and lower between 9 am and 5 pm. At the end of the noninfusion period, the 24-hr profile of the nonprotein respiratory quotient showed a slight decrease in patients receiving the cyclic infusion, in contrast with the stability of the quotient in the standard regimen. However, the nitrogen balance and variations in nutritional status did not differ significantly. In conclusion cyclic TPN is efficient for achieving a positive energy and nitrogen balance and in addition it induces a metabolic profile closer to physiological conditions.     

全胃切除术后早期肠内肠外营养的对比研究

目的：探讨全胃切除术后早期肠内营养（EEN）与全肠外营养（TPN）对患者营养状况的改善及并发症发生率的影响。方法：将86例接受根治性全胃切除的胃癌患者随机分为EEN组和TPN组。EEN组手术后第1天开始分别给予营养支持,于术前1天、术后8天检测体重、血常规、肝功能、前白蛋白和C-反应蛋白,并观察并发症的发生率和平均住院费用。结果：EEN组体重、白蛋白、前白蛋白下降幅度和白细胞、转氨酶、C-反应蛋白升高幅度均少于TPN组。EEN组患者吻合口瘘、肺部感染、切口愈合不良等并发症发病率低于TPN组。EEN组的平均住院费用低于TPN组。结论：术后EEN较TPN能改善全胃切除术后患者的营养状况,降低并发症发生率,减少经济费用。     

Comparison of substrate utilization by indirect calorimetry during cyclic and continuous total parenteral nutrition

Five male adult home patients were studied in a randomized order under continuous (24 h/d) and nocturnal cyclic (15 h/d) isocaloric, isonitrogenous total parenteral nutrition (TPN). They received 2626 +/- 265 total kcal/d as 60% dextrose and 40% lipids; the 3-h lipid infusion was followed by the dextrose amino acid infusion on both regimens. Substrate oxidation was measured by indirect calorimetry during four periods on the fourth day of each regimen. During cyclic TPN net lipogenesis occurred with a nonproteic respiratory quotient (npRQ) greater than 1 during dextrose amino acid infusion followed by net lipolysis with an npRQ less than 1 during the nonnourishing phase. In contrast, during continuous TPN net lipogenesis persisted with an npRQ greater than 1 over the 21 h of dextrose amino acid infusion. During the 3-h lipid infusion, fat oxidation was observed during both regimens but was more pronounced during cyclic TPN (p less than 0.05). As a consequence, 24-h lipid oxidation was higher and 24-h dextrose utilization lower during cyclic vs continuous TPN (p less than 0.05). These results suggest that cyclic TPN when alternating between substrate storage and oxidation, mimics the physiological pattern of oral feeding.     

Effect of continuous and discontinuous intravenous or intragastric total parenteral nutrition in rats on serum lipids, liver lipids and liver lipogenic rates

Lipogenesis and evidence of fat accumulation in the liver were investigated in adult male rats fed a hypertonic dextrose diet by continuous (C) and discontinuous (D) intravenous (IV) or intragastric (IG) infusion for 14 d. Rats fed by the IV and IG route were infused continuously and discontinuously (2100-0900) with 55 ml/d of a solution containing 30% dextrose and 2.72% amino acids plus vitamins and minerals. An orally (Or) fed group was fed 21.2 g of a solid diet, which provided an equivalent amount of calories and nitrogen as the infusion diet. Serum lipids, glucose, and insulin levels, de novo fatty acid synthesis in adipose tissue and liver, and the content of liver lipids were not altered by feeding the diet IV or IG. De novo lipogenesis was elevated in the livers of the continuously and discontinuously infused IV-or IG-fed rats compared with Or-fed rats. Fat accumulated in the livers of the rats infused continuously but not in the livers of the rats fed DIV, DIG or Or. Discontinuous feeding was associated with the mobilization of fatty acids that are necessary for lipoprotein formation and transport from the liver, which may explain, in part, why discontinuously infused rats do not develop fatty livers. These data indicate that cycling the total parenteral infusion may have clinical importance.     

早期全肠外营养及肠内、外混合营养对神经外科危重患者免疫功能的影响

目的探讨早期给予全肠外营养（TPN）及肠内营养（EN）、肠外营养（PN）混合支持对神经外科危重患者免疫功能的影响。方法采用前瞻性对照研究将神经外科危重患者按入院顺序随机分为TPN组及EN＋PN组,并对比营养支持前后两组CD3、CD4、CD8、CD4／CD8、CD3／CD25、IgA、IgG、IgM、血清白蛋白的变化。结果给予神经外科危重患者两种营养支持均可提高其CD3、CD4、CD8及CD3＋／CD25＋比值（P〈0．05,P〈0．01）;两种营养支持方式均可显著升高IgA、IgG、IgM、（P〈0．05）及血清白蛋白浓度（P〈0．01）。与TPN组比较,EN＋PN组CD3、CD4、CD8、CD4／CD8比值、IgA、IgG、IgM浓度及血清白蛋白水平均显著升高（P〈0．05,P〈0．01）。结论早期TPN及EN＋PN支持均可促进神经外科危重患者免疫功能的恢复及提高,EN＋PN的作用优于TPN,对于神经外科危重患者应早期给予营养支持治疗。     

Metabolic and thermogenic response to continuous and cyclic total parenteral nutrition in traumatised and infected patients

16 traumatised or infected patients on mechanical ventilation were randomised to continuous TPN or to cyclic TPN after a 24-h period of glucose infusion (1.25 kJ x kg BW(-1) x h(-1)). Energy supply was equivalent to 1.3 x baseline energy expenditure. Glucose, fat and amino acids were administered at a constant rate over 24 h in the continuous TPN group and over 12 h, followed by glucose (1.25 kJ x kg BW(-1) x h(-1)), in the cyclic TPN group. Nutrient-induced thermogenesis was lower during continuous than during cyclic TPN (5 +/- 4 vs. 12 +/- 7%, mean +/- SD, p < 0.05), as was the increase in CO(2) elimination (13 +/- 11 vs. 30 +/- 7%, respectively, p < 0.01). Energy balance was more positive during continuous TPN. In both groups, energy expenditure reached a plateau during the first 12 h of TPN infusion. The lower nutrient-induced thermogenesis and more positive energy balance, indicates a more efficient utilisation of nutrients during continuous than during cyclic TPN. The lower CO(2) production during continuous TPN, may be advantageous when respiratory function is compromised. The plateau in energy expenditure in response to TPN infusion may be useful as a guideline for nutritional therapy.     

Effects of enteral and parenteral nutrition on appetite in monkeys.

Varied clinical observations of the presence of either hunger or anorexia during intragastric or intravenous alimentation have led to the current experiments. Nine rhesus monkeys (Macaca mulatta) were involved in studies of the long-term effects of enteral and parenteral nutrition on appetite as assessed by feeding behavior and gastric motility. The monkeys received either intragastric infusions of glucose or a complete liquid diet, or intravenous infusions of glucose or glucose/amino acid solutions. Oral intake was accurately adjusted to account for the calories administered by the intragastric route. Oral intake was also reduced in a calorically equivalent amount to account for the calories received during intravenous glucose. When glucose/amino acid solutions were administered parenterally, adjustments were less accurate, with resultant overeating and weight gain in some monkeys during parenteral nutrition, followed by prolonged suppression of appetite after cessation of the infusions. Further studies of the effects of varied compositions of parenteral nutrition, and varied methods of weaning from infusions, are indicated.     

重症急性胰腺炎早期肠内外营养支持的临床对比研究

目的 分析比较肠内与肠外营养支持对重症急性胰腺炎(SAP)患者的影响,从而探讨经胃镜放置鼻空肠营养管行肠内营养支持在SAP中的临床应用价值.方法 分析2003年3月至2008年3月因SAP住院的患者,其中经胃镜放置鼻空肠营养管行早期肠内营养支持的患者35例(NENE组),并选择同期行完全胃肠外营养支持的患者35例作为对照组(TPN组),比较两组患者治疗前、治疗后1、2、3、4周血红蛋白、血清白蛋白、血肌酐、血胆固醇、三酰甘油及空腹血糖水平的变化,以及治疗前、治疗后4周免疫功能水平,并比较两组患者的住院时间、住院费用、各种并发症的发生情况和病死率.结果 治疗后,两组患者营养状况均有改善,但NENE组的血红蛋白升高和空腹血糖的下降较TPN组更为明显(P<0.05).而免疫功能测定表明治疗后NENE组IgA、CD4/CD8明显高于TPN组(P<0.05).而并发症方面,NENE组发生率明显低于TPN组(P<0.05).此外,NENE组的平均住院时间和住院费用明显少于TPN组[分别为(38.46±20.08)d比(57.75±26.69)d与(60716.24±42 357.35)元比(93 852.70±76493.62)元](P<0.01);但两组病死率比较差异无统计学意义(P>0.05).结论 SAP患者应尽早给予肠内营养有利于改善全身营养状况,增强机体免疫功能,显著减少各种感染、多脏器功能衰竭等并发症的发生率,缩短患者的住院时间和住院费用,其价值更优于TPN.     

Effects of soluble fiber (Plantago ovata husk) on plasma lipids, lipoproteins, and apolipoproteins in men with ischemic heart disease

BACKGROUND: New dietary strategies to reduce cardiovascular disease (CVD) risk include the addition of fiber to the diet. The effect of soluble-fiber consumption derived from Plantago ovata husk on lipid risk factors in patients with CVD is unknown. OBJECTIVE: We compared the effects of soluble fiber (P. ovata husk) with those of insoluble fiber (P. ovata seeds) on plasma lipid, lipoprotein, and apolipoprotein (apo) concentrations within a CVD secondary prevention program. DESIGN: In a randomized, crossover, controlled, single-blind design, 28 men with CVD (myocardial infarction or stable angina) and an LDL-cholesterol concentration 相似文献   

Short-term parenteral nutrition with glucose and Intralipid: effects on serum lipids and lipoproteins

We prospectively investigated the effect of a 3-wk course of parenteral nutrition with 20% glucose, 4.25% amino acids, and 10% Intralipid on plasma lipids and lipoproteins in a cohort of 12 nutritionally replete patients with inflammatory bowel disease. Mean total serum cholesterol and mean total serum phospholipids increased in parallel throughout the study; density gradient ultracentrifugation demonstrated these increases were due to the appearance of lipoprotein-X. The mean low-density lipoprotein (LDL) mass on the density gradients decreased during the study and high-density lipoprotein (HDL) cholesterol levels decreased by 28% by the end of the third week. Plasma free fatty acids decreased by 42%. These results demonstrate that the glucose and 10% Intralipid regimen caused modest decreases in serum HDL cholesterol and LDL mass and the prompt appearance of lipoprotein-X with attendant hypercholesterolemia and hyperphospholipidemia. Patients undergoing long-term treatment with glucose and Intralipid should be closely monitored for the occurrence of significant dyslipoproteinemia.     

Gastric pepsin and acid secretion during total parenteral nutrition and constant-rate enteral nutrition in infancy

Total Parenteral Nutrition (TPN) and constant rate enteral nutrition (CREN) are widely used: their effects on gastric function, especially pepsin secretion, are unknown. Basal and pentagastrin-stimulated pepsin (BPO, MPO) and acid (BAO, MAO) secretions were measured in three groups of infants: controls (14 infants fed normally), TPN groups (seven infants on TPN), CREN groups (14 infants on CREN). The MAO and MPO of the TPN group were significantly lower than controls (p less than 0.02), and the ratio of pentagastrin-stimulated PO/AO did not change, suggesting a large decrease of acid gastric function in the TPN group. BPO was not different from controls and BAO was significantly higher because of amino acids perfusion. The data for CREN group were not different from those of the control group, despite the fact that 11 infants were on TPN before CREN. These results demonstrate that TPN causes decreases in both acid and pepsin secretions in human infants. When TPN children are placed on CREN, these secretions return to normal.     

特重型颅脑损伤肠外肠内的序贯营养支持

目的：探讨特重型颅脑损伤早期全肠外（ＴＰＮ）营养逐步过渡为肠内营养支持的临床及合理性。 方法：营养组：１７例ＧＣＳ≤５分特重型颅脑损伤病人伤后２天开始应用ＴＰＮ,６￣７天后根据病情逐渐给予部分肠内营养（ＥＮ）过渡,１０天后改为完全的ＥＮ。观察血清、白蛋白、淋巴细胞计数、并发症发生率及预后。对照组：常规治疗的２０例特重型颅脑损伤作对照。 结果：特重型颅脑损伤病人能从早期的ＴＰＮ中获得较充分的能量和蛋