244 research outputs found

    Amino acid losses during hemodialysis with infusion of amino acids and glucose

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    Amino acid losses during hemodialysis with infusion of amino acids and glucose. This study evaluated the effects during hemodialysis of intravenous infusion of amino acids and glucose on plasma amino acid and glucose concentrations and amino acid losses. Eight men undergoing maintenance hemodialysis were each studied during two dialyses using glucose-free dialysate. During one hemodialysis, they were infused with 800ml of normal saline. During the other hemodialysis, they were infused with an equal volume of water which contained 39.5g of essential and non-essential free L-amino acids and 200g of d-glucose. The solutions were infused throughout the dialysis procedure into the drip chamber of the venous outflow from the dialyzer. Subjects were fasted from the night before until the end of hemodialysis, and the order of administration of the two solutions was determined randomly. Plasma essential, non-essential, and total amino acids fell significantly during the infusion of normal saline and rose during the administration of amino acids and glucose. Dialysate total-free amino acid losses averaged 8.2 ± 3.1SDg during the infusion of normal saline and 12.6 ± 3.6g with the administration of amino acids and glucose. These findings indicate that the intravenous infusion of amino acids and glucose during hemodialysis prevents a fall in plasma amino acid and glucose concentrations and leads to only a slight increase in the losses of free amino acids into dialysate. Because most of the infused amino acids are retained, this technique may be used during hemodialysis to avoid a net outflow of amino acids, minimize disruption of amino acid and glucose pools, and provide a nutritional supplement.Pertes en amino-acides au cours de l'hĂ©modialyse avec perfusion d'acides aminĂ©s et de glucose. Cette Ă©tude a permis d'Ă©valuer les effets de la perfusion intraveineuse d'acides aminĂ©s et de glucose pendant l'hĂ©modialyse sur les concentrations plasmatiques d'acides aminĂ©s et de glucose, et les pertes d'acides aminĂ©s. Huit hommes en hĂ©modialyse chronique ont chacun Ă©tĂ© Ă©tudiĂ©s pendant deux dialyses avec un dialysat sans glucose. Pendant une des dialyses ils Ă©taient perfusĂ©s avec 800ml de solutĂ© physiologique. Pendant l'hemodialyse autre ils ont infusĂ© avec un Ă©gal volume d'eau contenant 39,5g de L-acides aminĂ©s libres essentiels ou non, et 200g de d-glucose. Les solutions Ă©taient perfusĂ©es pendant la dialyse dans la tubulure veineuse venant du dialyseur. Les malades Ă©taient Ă  jeĂ»n la nuit prĂ©cĂ©dante et jusqu'Ă  la fin de la dialyse, et l'ordre d'administration des deux solutions Ă©tait dĂ©terminĂ© au hasard. Les acides aminĂ©s plasmatiques totaux, essentiels et non essentiels ont significativement diminuĂ© pendant la perfusion de solutĂ© physiologique, et se sont Ă©levĂ©s pendant l'administration d'acides aminĂ©s et de glucose. Dans le dialysat, les pertes totales d'acides aminĂ©s libres Ă©taient en moyenne de 8,2 ± 3,1g (ds) pendant la perfusion de solutĂ© physiologique, et de 12,6 ± 3,6g lors de l'administration d'acides aminĂ©s et de glucose. Ces rĂ©sultats indiquent que la perfusion intraveineuse d'acides aminĂ©s et de glucose au cours de la dialyse empĂȘche la chute des acides aminĂ©s et du glucose plasmatiques et n'occasionne qu'une diminution minime des pertes en acides aminĂ©s libres dans le dialysat. Puisque la plupart des acides aminĂ©s perfusĂ©s est retenue, cette technique pourrait ĂȘtre utilisĂ©e pendant l'hĂ©modialyse pour Ă©viter une fuite nette d'acides aminĂ©s, pour minimiser la dissipation des rĂ©serves d'acides aminĂ©s et de glucose et pour apporter un supplĂ©ment nutritif

    Risks of chronic metabolic acidosis in patients with chronic kidney disease

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    Risks of chronic metabolic acidosis in patients with chronic kidney disease Metabolic acidosis is associated with chronic renal failure (CRF). Often, maintenance dialysis therapies are not able to reverse this condition. The major systemic consequences of chronic metabolic acidosis are increased protein catabolism, decreased protein synthesis, and a negative protein balance that improves after bicarbonate supplementation. Metabolic acidosis also induces insulin resistance and a decrease in the elevated serum leptin levels associated with CRF. These three factors may promote protein catabolism in maintenance dialysis patients. Available data suggest that metabolic acidosis is both catabolic and anti-anabolic. Several clinical studies have shown that correction of metabolic acidosis in maintenance dialysis patients is associated with modest improvements in nutritional status. Preliminary evidence indicates that metabolic acidosis may play a role in ÎČ2-microglobulin accumulation, as well as the hypertriglyceridemia seen in renal failure. Interventional studies for metabolic acidosis have yielded inconsistent results in CRF and maintenance hemodialysis patients. In chronic peritoneal dialysis patients, the mitigation of acidemia appears more consistently to improve nutritional status and reduce hospitalizations. Large-scale, prospective, randomized interventional studies are needed to ascertain the potential benefits of correcting acidemia in maintenance hemodialysis patients. To avoid adverse events, an aggressive management approach is necessary to correct metabolic acidosis. Clinicians should attempt to adhere to the National Kidney Foundation Kidney Disease Outcome Quality Initiative (K/DOQI) guidelines for maintenance dialysis patients. The guidelines recommend maintenance of serum bicarbonate levels at 22 mEq/L or greater

    Metabolic balance studies and dietary protein requirements in patients undergoing continuous ambulatory peritoneal dialysis

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    Metabolic balance studies and dietary protein requirements in patients undergoing continuous ambulatory peritoneal dialysis. Balance studies for nitrogen, potassium, magnesium, phosphorus, and calcium were carried out in eight men undergoing continuous ambulatory peritoneal dialysis (CAPD) to determine dietary protein requirements and mineral balances. Patients were fed high energy diets for 14 to 33 days which provided either 0.98 (seven studies) or 1.44g (six studies) of primarily high biological value protein/kg body wt/day. Mean nitrogen balance was neutral with the lower protein diet (+0.35 ± 0.83SEMg/day) and strongly positive with the higher protein diet (+2.94 ± 0.54g/day). With the higher protein diet the balances for potassium, magnesium, and phosphorus were strikingly positive, there was an increase in body weight in all patients, and a rise in mid-arm muscle circumference in five of the six patients. The relation between protein intake and nitrogen balance suggests that the daily protein requirement for clinically stable CAPD patients should be at least 1.1g/kg/day; to account for variability among subjects 1.2 to 1.3g protein/kg/day is probably preferable. Potassium balance correlated directly with nitrogen balance (r = 0.81). High fecal potassium losses (19 ± 1.2 mEq/day) in all patients probably helped maintain normal serum potassium concentrations. Mean serum magnesium was increased (3.1 ± 0.1 mg/dl), and magnesium balances were positive suggesting that the dialysate magnesium of 1.85 mg/dl is excessive. The netgain of calcium from dialysate was 84 ± 18 mg/day; this correlated inversely with serum calcium levels (r = -0.90).Bilans mĂ©taboliques et besoins protĂ©iques alimentaires de malades en dialyse pĂ©ritonĂ©ale continue ambulatoire. Des Ă©tudes de bilan de l'azote, du potassium, du magnĂ©sium, du phosphore et du calcium, Ă©taient fait en sept hommes en dialyse pĂ©ritonĂ©ale continue ambulatoire (CAPD), pour dĂ©terminer leurs besoins protĂ©iques alimentaires et leur bilan minĂ©ral. Les malades ont reçu pendant 14 Ă  33 jours des rĂ©gimes hautement Ă©nergĂ©tiques, apportant soit 0,98 (sept Ă©tudes), soit 1,44g (six Ă©tudes) de protĂ©ines de haute valeur biologique par kg de poids et par jour. Le bilan azotĂ© moyen etait nul avec le rĂ©gime comportant la plus faibie teneur protĂ©ique (+ 0,35 ± 0,88g/jSEM) et Ă©tait fortement positive avec le rĂ©gime Ă  plus forte teneur protĂ©ique (+2,94 ± 0,54g/j). Avec le rĂ©gime Ă  haute teneur en protĂ©ine, les bilans potassique, magnĂ©sien et phosphorĂ© Ă©taient fortement positifs; le poids corporel s'est Ă©levĂ© chez tous les malades; la circonfĂ©rence musculaire mesurĂ©e du milieu du bras a augmentĂ© chez cinq sur six malades. La relation existant entre l'apport protĂ©ique et le bilan azotĂ© suggĂšre que les besoins journaliers en protĂ©ines pour des malades cliniquement stables en CAPD devraient ĂȘtre au moins de 1,1g/kg/j; 1,2 Ă  1,3g de protĂ©ines/kg/j sont sans doute prĂ©fĂ©rables pour tenir compte de la variabilitĂ© entre les sujets. Le bilan potassique Ă©tait directement corrĂ©lĂ© avec la balance azotĂ©e (r = 0,81). De fortes pertes potassiques fĂ©cales (19 ± 1,2 mEq/j) chez tous les malades ont probablement contribuĂ© Ă  maintenir normales les concentrations sĂ©riques du potassium. La magnĂ©sĂ©mie moyenne Ă©tait Ă©levĂ©e (3,1 ± 0,1 mg/dl), et les bilans magnĂ©siens aient positifs suggĂ©rant que le magnĂ©sium du dialysat (1,85 18 mg/dl) Ă©tait trop Ă©levĂ©. Le gain net en calcium Ă  partir du dialysat Ă©tait de 84 ± 18 mg/j; ce gain Ă©tait inversement corrĂ©lĂ© avec la calcĂ©mie (r = 0,90)

    Glucose absorption during continuous ambulatory peritoneal dialysis

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    Glucose absorption during continuous ambulatory peritoneal dialysis. Patients undergoing continuous ambulatory peritoneal dialysis (CAPD) are exposed to a continuous infusion of glucose via their peritoneal cavity. We performed studies to quantitate the amount of energy derived from dialysate glucose. Net glucose absorption averaged 182 ± (SD) 61 g/day in 19 studies with a dialysate dextrose concentration of 1.5 or 4.25 g/dl. The amount of glucose absorbed per liter of dialysate (y) varied with the concentration of glucose in dialysate (x), (y = 11.3x - 10.9, r = 0.96), The amount of glucose absorbed per day during a given dialysis regimen was constant. Energy intake from dialysate glucose was 8.4 ± 2.8 kcal/kg of body wt per day, or 12 to 34% of total energy intake. This additional energy may contribute to the anabolic effect reported during CAPD. The ability to vary glucose absorption by altering the dialysate glucose concentration may prove a useful tool to modify energy intake.Absorption de glucose au cours de la dialyse pĂ©ritonĂ©ale continue ambulatoire. Les malades soumis Ă  la dialyse pĂ©ritonĂ©ale continue ambulatoire (CAPD) sont exposĂ©s Ă  une administration continue de glucose via leur cavitĂ© pĂ©ritonĂ©ale. La quantitĂ© d'Ă©nergie qui dĂ©rive du glucose du dialysat a Ă©tĂ© quantifiĂ©e. L'absorption nette de glucose est en moyenne de 182 ± (SD) 61 g/jour au cours de 19 Ă©tudes avec un dialysat contenant du dextrose, 1,5 ou 4,25 g/dl. La quantitĂ© de glucose absorbĂ©e par litre de dialysat (y) varie avec la concentration de glucose dans le dialysat (x), (y = 11,3x - 10,9, r = 0,96). La quantitĂ© de glucose absorbĂ©e par jour pour un type donnĂ© de dialyse a Ă©tĂ© constante. L'entrĂ©e d'Ă©nergie Ă  partir du glucose du dialysat Ă©tait de 8,4 ± 2,8 kcal/kg de poids par jour, soit 12 Ă  34% de l'entrĂ©e totale d'Ă©nergie. Cette Ă©nergie supplĂ©mentaire peut contribuer Ă  l'effet anabolique rapportĂ© au cours de CAPD. La possibilitĂ© de faire varier l'absorption de glucose en modifiant la concentration de glucose dans le dialysat peut ĂȘtre un moyen utile pour influencer l'entrĂ©e d'Ă©nergie

    Effect of dietary protein restriction on nutritional status in the Modification of Diet in Renal Disease Study

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    Effect of dietary protein restriction on nutritional status in the Modification of Diet in Renal Disease Study. The safety of dietary protein and phosphorous restriction was evaluated in the Modification of Diet in Renal Disease (MDRD) Study. In Study A, 585 patients with a glomerular filtration rate (GFR) of 25 to 55 ml/min/1.73m2 were randomly assigned to a usual-protein diet (1.3 g/kg/day) or a low-protein diet (0.58 g/kg/day). In Study B, 255 patients with a GFR of 13 to 24 ml/min/1.73m2 were randomly assigned to the low-protein diet or a very-low-protein diet (0.28 g/kg/day), supplemented with a ketoacid-amino acid mixture (0.28 g/kg/day). The low-protein and very-low-protein diets were also low in phosphorus. Mean duration of follow-up was 2.2 years in both studies. Protein and energy intakes were lower in the low-protein and very-low-protein diet groups than in the usual-protein group. Two patients in Study B reached a “stop point” for malnutrition. There was no difference between randomized groups in the rates of death, first hospitalizations, or other “stop points” in either study. Mean values for various indices of nutritional status remained within the normal range during follow-up in each diet group. However, there were small but significant changes from baseline in some nutritional indices, and differences between the randomized groups in some of these changes. In the low-protein and very-low-protein diet groups, serum albumin rose, while serum transferrin, body wt, percent body fat, arm muscle area and urine creatinine excretion declined. Combining patients in both diet groups in each study, a lower achieved protein intake (from food and supplement) was not correlated with a higher rate of death, hospitalization or stop points, or with a progressive decline in any of the indices of nutritional status after controlling for baseline nutritional status and follow-up energy intake. These analyses suggest that the low-protein and very-low-protein diets used in the MDRD Study are safe for periods of two to three years. Nonetheless, both protein and energy intake declined and there were small but significant declines in various indices of nutritional status. These declines are of concern because of the adverse effect of protein calorie malnutrition in patients with end-stage renal disease. Physicians who prescribe low-protein diets must carefully monitor patients' protein and energy intake and nutritional status

    Dietary Protein Intake and Survival in 100,088 Maintenance Hemodialysis Patients: The Role of Race and Albumin

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    Decreased dietary protein intake may be associated with increased mortality risk in individuals undergoing maintenance hemodialysis (MHD). We examined 8−year all-cause mortality in 100,088 MHD patients from DaVita dialysis clinics in the US (2001–2009) and hypothesized that survival is better across higher levels of nPNA, (nPCR, a dietary protein intake surrogate) with consistent trends across race and in hypoalbuminemic patients. Time-averaged Cox models were used to estimate death hazard ratios for quarterly averaged nPNA categories controlled for case-mix, comorbidity, dialysis dose, and available markers of malnutrition-inflammation-complex syndrome (MICS). In all patients, both low (<0.6g/kg/day, HR 1.53, [1.47–1.59]) and high nPNA (≄1.4g/kg/day, HR 1.26, [1.19-1.34]) were associated with higher all-cause mortality when compared with the reference (1.0–<1.1g/kg/day). This reverse–J–shape association was also found in sub-analyses performed among racial groups and in hypoalbuminemic patients (Figure). Hence, hypoalbuminemic patients of all races may benefit from higher protein intake, which needs controlled trial to verify
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