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ABSTRACT: CONTEXT: Inadequate dietary protein intake has been implicated in sarcopenia. OBJECTIVE AND DESIGN: The objectives of this study were to determine whether: 1) chronic essential amino acid (EAA) supplementation improves postabsorptive muscle protein fractional synthesis rate (FSR), lean body mass (LBM), and one-repetition maximum muscle strength, and androgen receptor and IGF-I muscle protein expression; and 2) the acute anabolic response to EAA ingestion is preserved after a 3-month supplementation period. Using a randomized, double-blinded, placebo-controlled design, older women (68 +/- 2 yr) were assigned to receive either placebo (n = 7), or 15 g EAA/d [supplemented treatment group (SUP)] (n = 7) for 3 months. Metabolic outcomes were assessed in association with stable isotope studies conducted at 0 and 3 months. SETTING: The study was performed at The University of Texas Medical Branch General Clinical Research Center. RESULTS: Ingestion of 7.5 g EAA acutely stimulated FSR in both groups at 0 months (P < 0.05). Basal FSR at 3 months was increased in SUP only. The magnitude of the acute response to EAA was unaltered after 3 months in SUP. LBM increased in SUP only (P < 0.05). One-repetition maximum strength remained unchanged in both groups. Basal IGF-I protein expression increased in SUP after 3 months (P = 0.05), with no changes in androgen receptor or total and phosphorylated Akt, mammalian target of rapamycin, S6 kinase, and 4E-binding protein. CONCLUSIONS: EAA improved LBM and basal muscle protein synthesis in older individuals. The acute anabolic response to EAA supplementation is maintained over time and can improve LBM, possibly offsetting the debilitating effects of sarcopenia.
J Clin Endocrinol Metab. 01/2009; 94(5):1630-7.
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Journal of burn care & research: official publication of the American Burn Association 02/2006; 27(2):S131. · 1.37 Impact Factor
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Journal of Physiology-london - J PHYSIOL-LONDON. 01/2006; 576(2):613-624.
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ABSTRACT: Regular aerobic exercise strongly influences muscle metabolism in elderly and young; however, the acute effects of aerobic exercise on protein metabolism are not fully understood. We investigated the effect of a single bout of moderate walking (45 min at approximately 40% of peak O2 consumption) on postexercise (POST-EX) muscle metabolism and synthesis of plasma proteins [albumin (ALB) and fibrinogen (FIB)] in untrained older (n = 6) and younger (n = 6) men. We measured muscle phenylalanine (Phe) kinetics before (REST) and POST-EX (10, 60, and 180 min) using l-[ring-2H5]phenylalanine infusion, femoral arteriovenous blood samples, and muscle biopsies. All data are presented as the difference from REST (at 10, 60, and 180 min POST-EX). Mixed muscle fractional synthesis rate (FSR) increased significantly at 10 min POST-EX in both the younger (0.0363%/h) and older men (0.0830%/h), with the younger men staying elevated through 60 min POST-EX (0.0253%/h). ALB FSR increased at 10 min POST-EX in the younger men only (2.30%/day), whereas FIB FSR was elevated in both groups through 180 min POST-EX (younger men = 4.149, older men = 4.107%/day). Muscle protein turnover was also increased, with increases in synthesis and breakdown in younger and older men. Phe rate of disappearance (synthesis) was increased in both groups at 10 min POST-EX and remained elevated through 60 min POST-EX in the older men. A bout of moderate-intensity aerobic exercise induces short-term increases in muscle and plasma protein synthesis in both younger and older men. Aging per se does not diminish the protein metabolic capacity of the elderly to respond to acute aerobic exercise.
AJP Endocrinology and Metabolism 10/2004; 287(3):E513-22. · 4.75 Impact Factor
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ABSTRACT: The catecholamine-mediated hypermetabolic response to severe burns causes increased energy expenditure and muscle-protein catabolism. We hypothesized that blockade of beta-adrenergic stimulation with propranolol would decrease resting energy expenditure and muscle catabolism in patients with severe burns.
Twenty-five children with acute and severe burns (more than 40 percent of total body-surface area) were studied in a randomized trial. Thirteen received oral propranolol for at least two weeks, and 12 served as untreated controls. The dose of propranolol was adjusted to decrease the resting heart rate by 20 percent from each patient's base-line value. Resting energy expenditure and skeletal-muscle protein kinetics were measured before and after two weeks of beta-blockade (or no therapy, in controls). Body composition was measured serially throughout hospitalization.
Patients in the control group and the propranolol group were similar with respect to age, weight, percentage of total body-surface area burned, percentage of body-surface area with third-degree burns, and length of time from injury to metabolic study. Beta-blockade decreased the heart rates and resting energy expenditure in the propranolol group, both as compared with the base-line values (P<0.001 and P=0.01, respectively) and as compared with the values in the control group (P=0.03 and P=0.001, respectively). The net muscle-protein balance increased by 82 percent over base-line values in the propranolol group (P=0.002), whereas it decreased by 27 percent in the control group (P not significant). The fat-free mass, as measured by whole-body potassium scanning, did not change substantially in the propranolol group, whereas it decreased by a mean (+/-SE) of 9+/-2 percent in the control group (P=0.003).
In children with burns, treatment with propranolol during hospitalization attenuates hypermetabolism and reverses muscle-protein catabolism.
New England Journal of Medicine 10/2001; 345(17):1223-9. · 53.30 Impact Factor
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ABSTRACT: Delays in growth are commonly observed in children who have sustained a severe cutaneous burn. The reasons for this growth delay are not completely known, but in adults, plasma growth hormone (GH) levels have been shown to decrease after thermal injury. If this is also the case in severely burned children, the low GH levels may contribute to their chronic growth delay. We propose that treatment with rhGH may prevent this burn-induced growth delay. Height velocities were measured for up to 2 years after injury in 38 burned children (age 7+/-1 years) with a 64+/-2% total burn surface area (TBSA) burn and a 59+/-3% third-degree burn who received 0.2 mg/kg/day rhGH during hospitalization. These height velocities were compared to 41 burned children (age 8+/-1 years) with a 64+/-3% TBSA burn and a 60+/-3% TBSA third-degree burn who were treated similarly but did not receive rhGH. Height velocities and height percentiles were compared to standard height velocity and percentile nomograms of unburned children. To determine the effect of rhGH on energy requirements, resting energy expenditures (REE) were measured by indirect calorimetry and compared to values calculated from the Harris-Benedict equation. All data are presented as mean+/-S.E.M. No differences in average height percentile could be shown between those receiving GH and controls at admission and 6 months after burn. There was, however, a significant difference (P<0.05) in height velocity during the first 2 years after burn between GH (47th+/-6 percentile) and controls (32nd+/-5 percentile). For rhGH-treated children, the REE was elevated by 34+/-4% versus 35+/-5% for controls. Recombinant human GH, given during acute hospitalization, maintained growth in severely burned children who would otherwise experience a significant growth delay. Treatment with rhGH did not atttenuate their elevated REE.
Burns 09/2001; 27(5):447-52. · 1.96 Impact Factor
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ABSTRACT: Excisional therapy for burn wounds is frequently associated with large operative blood losses. Our objective was to identify patient and operative factors that affect surgical blood loss and determine strategies to minimize hemorrhage.
Data from 92 consecutive pediatric patients with severe burns (>40% total body surface area) were evaluated. Patient demographics, burn characteristics, operative factors, and clinical course variables were correlated with blood loss. Blood loss at the time of initial total burn excision was determined by a standardized, previously validated method. Data were analyzed sequentially and cumulatively through univariate and cross-sectional multivariate linear regression.
Demographic factors that correlated with increased blood loss were older age, male sex, and larger body size. Area of full-thickness (third-degree) burn correlated with blood loss, whereas total burn size did not. High wound bacteria counts (derived from quantitative tissue cultures), total wound area excised, and operative time were the strongest predictors of the volume of operative hemorrhage. Blood loss increased with delay to primary burn excision at a maximum at 5 to 12 days after burn injury.
Early definitive surgical therapy before extensive bacterial colonization and rapid operative excision is a strategy that may decrease operative hemorrhage and transfusion requirements during burn surgical procedures.
Surgery 08/2001; 130(2):396-402. · 3.10 Impact Factor
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ABSTRACT: To determine within the setting of isocaloric, isonitrogenous enteral diets whether a diet that supplies most of its calories from fat or carbohydrate would be most beneficial at limiting muscle protein wasting in catabolic illness.
Prospective, randomized, crossover trial.
Academic pediatric burn unit in tertiary medical center.
Fourteen severely burned (>40% total body surface area) children underwent systemic metabolic and cross-leg muscle protein kinetic studies.
All were treated clinically in a similar manner, including early excision and grafting, antimicrobial therapy, and isocaloric, isonitrogenous enteral nutritional support. Subjects randomly received either a high-carbohydrate enteral diet (3% fat, 82% carbohydrate, 15% protein), or a high-fat enteral diet (44% fat, 42% carbohydrates, 14% protein) for 1 week and then crossed over to the other diet for a second week.
On day 5 of each diet, muscle protein kinetics were determined from femoral arterial and venous blood samples during a primed-constant d5-phenylalanine infusion. Indirect calorimetry was used to determine systemic resting energy expenditure and respiratory quotient. The seven boys and seven girls were 7.1 +/- 1.1 (mean +/- sem) years old and suffered burns over 65 +/- 4% of their bodies, with 52 +/- 6% being third-degree burns. Muscle protein degradation markedly decreased (p <.01) with administration of the high-carbohydrate diet. Protein synthesis was unaltered. Endogenous insulin concentrations increased during the high-carbohydrate feeding period. No differences in energy expenditure were seen between study diets.
In severely burned pediatric patients, enteral nutrition supplied predominantly as carbohydrate rather than fat improves the net balance of skeletal muscle protein across the leg. This is attributable to decreased protein breakdown, suggesting a protein-sparing effect of high-carbohydrate feedings.
Critical Care Medicine 08/2001; 29(7):1318-24. · 6.33 Impact Factor
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ABSTRACT: To investigate the effect of a thermal injury on pulmonary surfactant phosphatidylcholine kinetics.
Random, controlled study.
University research laboratory.
Yorkshire swine (n = 8) with and without a 40% total body surface area burn.
A new isotope tracer methodology was used to quantify surfactant phosphatidylcholine kinetics. Four days after burn, [1,2-13C2]acetate and [U-(13)C16]palmitate were infused continuously for 8 hrs to quantify surfactant phosphatidylcholine synthesis, secretion, recycling, and irreversible loss.
The total surfactant phosphatidylcholine pool size was reduced from the control value of 2.65 +/- 0.05 to 1.61 +/- 0.08 micromol/g wet lung in burned animals (p <.05), as was the proportional contribution of palmitate to lung surfactant phosphatidylcholine composition. This reduction was associated with a significant decrease in lung dynamic compliance from the control value of 66 +/- 6 to 55 +/- 6 mL/cm H2O for burned pigs (p <.05). The most prominent response of lung phosphatidylcholine kinetics was a decrease in the total lung phosphatidylcholine synthesis from a control value of 12.7 +/- 1.2 to 5.5 +/- 0.3 nmol phosphatidylcholine-bound palmitate x hr(-1) x g of wet lung(-1) in burned animals (p<.05).
Pulmonary phosphatidylcholine content and palmitate composition decrease after burn injury because of a decrease in the rate of phosphatidylcholine synthesis. These responses likely contribute to impaired lung compliance.
Critical Care Medicine 08/2001; 29(7):1417-22. · 6.33 Impact Factor
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ABSTRACT: To determine whether the beneficial effects of growth hormone persist throughout the prolonged hypermetabolic and hypercatabolic response to severe burn.
The hypermetabolic response to severe burn is associated with increased energy expenditure, insulin resistance, immunodeficiency, and whole body catabolism that persists for months after injury. Growth hormone is a potent anabolic agent and salutary modulator of posttraumatic metabolic responses.
Seventy-two severely burned children were enrolled in a placebo-controlled double-blind trial investigating the effects of growth hormone (0.05 mg/kg per day) on muscle accretion and bone growth. Drug or placebo treatment began on discharge from the intensive care unit and continued for 1 year after burn. Total body weight, height, dual-energy x-ray absorptiometry, indirect calorimetry, and hormone values were measured at discharge, then at 6 months, 9 months, and 12 months after burn. Results were compared between groups.
Growth hormone subjects gained more weight than placebo subjects at the 9-month study point; this disparity in weight gain continued to expand throughout the remainder of the study. Height also increased in the growth hormone group compared with controls at 12 months. Change in lean body mass was greater in those treated with growth hormone at 6, 9, and 12 months. Bone mineral content was increased at 9 and 12 months; this was associated with higher parathormone levels.
Low-dose recombinant human growth hormone successfully abates muscle catabolism and osteopenia induced by severe burn.
Annals of Surgery 07/2001; 233(6):827-34. · 7.49 Impact Factor
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ABSTRACT: To explore the hypothesis that oxandrolone may reverse muscle catabolism in cachectic, critically ill pediatric burn patients.
Severe burn causes exaggerated muscle protein catabolism, contributing to weakness and delayed healing. Oxandrolone is an anabolic steroid that has been used in cachectic hepatitis and AIDS patients.
Fourteen severely burned children were enrolled during a 5-month period in a prospective cohort analytic study. There was a prolonged delay in the arrival of these patients to the burn unit for definitive care. This neglect of skin grafting and nutritional support resulted in critically ill children with significant malnutrition. On arrival, all patients underwent excision and skin grafting and received similar clinical care. Subjects were studied 5 to 7 days after admission, and again after 1 week of oxandrolone treatment at 0.1 mg/kg by mouth twice daily or no pharmacologic treatment. Muscle protein kinetics were derived from femoral arterial and venous blood samples and vastus lateralis muscle biopsies during a stable isotope infusion.
Control and oxandrolone subjects were similar in age, weight, and percentage of body surface area burned. Muscle protein net balance decreased in controls and improved in the oxandrolone group. The improvement in the oxandrolone group was associated with increased protein synthesis efficiency. Muscle protein breakdown was unchanged.
In burn victims, oxandrolone improves muscle protein metabolism through enhanced protein synthesis efficiency. These findings suggest the efficacy of oxandrolone in impeding muscle protein catabolism in cachectic, critically injured children.
Annals of Surgery 05/2001; 233(4):556-64. · 7.49 Impact Factor
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D W Hart,
S E Wolf, D L Chinkes,
D C Gore,
R P Mlcak,
R B Beauford,
M K Obeng,
S Lal,
W F Gold,
R R Wolfe,
D N Herndon
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ABSTRACT: To determine which patient factors affect the degree of catabolism after severe burn.
Catabolism is associated with severe burn and leads to erosion of lean mass, impaired wound healing, and delayed rehabilitation.
From 1996 to 1999, 151 stable-isotope protein kinetic studies were performed in 102 pediatric and 21 adult subjects burned over 20-99. 5% of their total body surface area (TBSA). Patient demographics, burn characteristics, and hospital course variables were correlated with the net balance of skeletal muscle protein synthesis and breakdown across the leg. Data were analyzed sequentially and cumulatively through univariate and cross-sectional multiple regression.
Increasing age, weight, and delay in definitive surgical treatment predict increased catabolism (P < .05). Body surface area burned increased catabolism until 40% TBSA was reached; catabolism did not consistently increase thereafter. Resting energy expenditure and sepsis were also strong predictors of net protein catabolism. Among factors that did not significantly correlate were burn type, pneumonia, wound contamination, and time after burn. From these results, the authors also infer that gross muscle mass correlates independently with protein wasting after burn.
Heavier, more muscular subjects, and subjects whose definitive surgical treatment is delayed are at the greatest risk for excess catabolism after burn. Sepsis and excessive hypermetabolism are also associated with protein catabolism.
Annals of Surgery 11/2000; 232(4):455-65. · 7.49 Impact Factor
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ABSTRACT: The primary goal of this study was to investigate the effects of glucose infusion on surfactant phosphatidylcholine (PC) metabolic kinetics in the lungs. A new stable isotope tracer model was used in which [1,2-(13)C(2)]acetate and uniformly labeled [U-(13)C(16)]palmitate were infused in 12 normal overnight-fasted pigs to quantify lung surfactant kinetics with or without glucose infusion (24 mg. kg(-1). min(-1)). With glucose infusion, the rate of surfactant PC incorporation from de novo synthesized palmitate increased from the control value of 2.1 +/- 0.2 to 15.5 +/- 1.9 nmol PC-bound palmitate. h(-1). g wet lung(-1) (P < 0.05), whereas the incorporation rate from plasma preformed palmitate decreased from the control value of 20.9 +/- 1.9 to 11.6 +/- 1.1 nmol palmitate. h(-1). g wet lung(-1) (P < 0.05). The palmitate composition in lamellar body surfactant PC increased from the control value of 61.7 +/- 2.1% to 75.9 +/- 0.6% (P < 0.05). The surfactant PC secretion rate decreased from the control value of 239.0 +/- 26.1 to 81.9 +/- 5.3 nmol PC-bound palmitate. h(-1). g wet lung(-1) (P < 0.05). We conclude that, whereas surfactant secretion was inhibited by glucose infusion, neither total surfactant PC synthesis nor the surfactant PC pool size was significantly affected due to an increased reliance on de novo synthesized fatty acids.
AJP Endocrinology and Metabolism 11/2000; 279(4):E920-6. · 4.75 Impact Factor
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ABSTRACT: A synthetic bilaminar membrane used as a skin substitute (Biobrane) has been shown to decrease pain and hospitalization in superficial second-degree burns. Despite these benefits, it has not been utilized universally, particularly in young children, due to a perceived increase in related infections. We propose that when this synthetic membrane is applied to superficial scald burns <25% of the total body surface area (TBSA), decreased healing times are expected without increased risk of infection. Between 1994-1999, 89 children treated within 48 h after receiving superficial partial thickness scald burns covering 5-25% TBSA with no indication of infection were seen at our hospital. Forty-one were assigned randomly to receive treatment with the skin substitute Biobrane and 48 to receive conservative treatment with topical antimicrobials and dressing changes. Comparisons of treatment were made between groups for length of hospitalization, wound healing times, and infectious complications. Children treated with Biobrane or topical antimicrobials were similar in age, race, sex, %TBSA burned, and location of burn. Those receiving Biobrane had shorter hospitalizations and healing times, which was significant for both infants and toddlers and older children. Treatment groups were not different in the use of systemic antibiotics or readmissions for infectious complications. Biobrane was removed in 5.9% of cases for non-adherence. The application of Biobrane within 48 h of superficial burns provides for shorter hospitalizations and faster healing times in children of all ages without increased risk of infection.
Shock 10/2000; 14(3):314-8; discussion 318-9. · 2.85 Impact Factor
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ABSTRACT: The hypermetabolic response to severe burn is characterized by muscle protein catabolism. Current opinion states that the hypermetabolic state resolves soon after complete wound closure. Clinically, we have witnessed that burned children appear to be hypermetabolic and catabolic long after full healing of their wounds. Our goal in this study was to determine scientifically if burn-associated hypermetabolism persists after full wound healing.
To determine the duration of muscle catabolism and systemic hypermetabolism after severe burn in children, patients with > 40% total body surface area burns were enrolled in a prospective, longitudinal study; resting energy expenditure was measured by indirect calorimetry, muscle protein kinetics were determined by using stable isotopic methodology, and body composition was measured by dual-energy x-ray absorptiometry imaging. Data were collected at 6, 9, and 12 months after injury.
The mean total body surface area burned was 65% +/- 13%, and the mean age was 7.6 +/- 1. 5 years. Resting energy expenditure was elevated above the predicted age-matched levels from the Harris-Benedict equation and incrementally declined throughout the 12-month study. The net protein balance and lean mass reflected catabolic persistence at 6 and 9 months after severe burn. Between 9 and 12 months, protein breakdown decreased, net protein balance improved, and lean body mass increased.
In severely burned children, hypermetabolism and catabolism remain exaggerated for at least 9 months after injury. This suggests that therapeutic attempts to manipulate the catabolic and hypermetabolic response to severe injury should be continued long after injury.
Surgery 08/2000; 128(2):312-9. · 3.10 Impact Factor
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ABSTRACT: The purpose of this study was to determine the anabolic effects of recombinant human insulin-like growth factor-I (rhIGF-1) complexed with its principal binding protein IGF-1 binding protein-3 (IGFBP-3) in severely burned adults.
Ten burned adults were studied consecutively after receiving saline (pretreatment), then rhIGF-1/IGFBP-3 (treatment) for 5 days. Doses were 1, 2, and 4 mg/kg per day. Glucose, electrolytes, hormones, and leg muscle protein metabolism were determined. Nine other studies were performed on similarly injured adults at comparable times to the treatment studies to control for time effects.
Serum IGF-1 and IGFBP-3 levels increased with all doses, but no incremental increases were found. Leg protein balance improved with rhIGF-1/IGFBP-3, which was associated with an increase in muscle protein fractional synthetic rate. These effects were independent of time. All patients were euglycemic without electrolyte imbalances.
Net protein synthesis in the isolated leg of severely burned adults improved with rhIGF-1/IGFBP-3 without development of glucose abnormalities.
The Journal of trauma 12/1999; 47(5):904-10; discussion 910-1. · 2.48 Impact Factor
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ABSTRACT: The primary goal of this study was to determine the contributions of plasma free fatty acids (FFA) and de novo synthesized fatty acids (FA) to lung surfactant phosphatidylcholine (PC) synthesis. A new stable isotope tracer model was developed in which [1, 2-(13)C(2)]acetate and uniformly labeled [U-(13)C(16)]palmitate were infused in nine normal overnight fasted pigs to quantify surfactant kinetics in the basal state and during low-dose glucose infusion (2 mg. kg(-1). min(-1)). There was no effect of glucose; therefore, all data were pooled. The surfactant PC-bound palmitate incorporation rate from plasma palmitate was 20.9 +/- 1.9 nmol palmitate. h(-1). g wet lung(-1), compared with the rate of 2.1 +/- 0.3 nmol palmitate. h(-1). g wet lung(-1) from de novo synthesized palmitate. The PC-bound palmitate secretion rate from the lamellar body pool to the alveolar surface pool was 239 +/- 26 nmol palmitate. h(-1). g wet lung(-1). Approximately 90% of the secreted PC recycled back to the lamellar bodies for reutilization. We conclude that plasma is the primary contributor of FA for surfactant PC synthesis under the conditions of this experiment.
The American journal of physiology 08/1999; 277(1 Pt 1):E187-95.
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ABSTRACT: To determine the effects of recombinant human insulin-like growth factor-1 (IGF-1) complexed with its principal binding protein, IGFBP-3, on skeletal muscle metabolism in severely burned children.
Severe burns are associated with a persistent hypermetabolic response characterized by hyperdynamic circulation and severe muscle catabolism and wasting. Previous studies showed that nutritional support and pharmacologic intervention with anabolic agents such as growth hormone and insulin abrogated muscle wasting and improved net protein synthesis in the severely burned. The use of these agents, however, has several adverse side effects. A new combination of IGF-1 and IGFBP-3 is now available for clinical study.
Twenty-nine severely burned children were prospectively studied before and after treatment with 0.5, 1, 2, or 4 mg/kg/day IGF-1/IGFBP-3 to determine net balance of protein across the leg, muscle protein fractional synthetic rates, and glucose metabolism. Another group was studied in a similar fashion without IGF-1/IGFBP-3 treatment as time controls.
Seventeen of 29 children were catabolic before starting treatment. The infusion of 1.0 mg/kg/day IGF-1/IGFBP-3 increased serum IGF-1, which did not further increase with 2.0 and 4.0 mg/kg/day. IGF-1/IGFBP-3 treatment at 1 to 4 mg/ kg/day improved net protein balance and increased muscle protein fractional synthetic rates. This effect was more pronounced in catabolic children. IGF-1/IGFBP-3 did not affect glucose uptake across the leg or change substrate utilization.
IGF-1/IGFBP-3 at doses of 1 to 4 mg/kg/day attenuates catabolism in catabolic burned children with negligible clinical side effects.
Annals of Surgery 06/1999; 229(5):713-20; discussion 720-2. · 7.49 Impact Factor
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ABSTRACT: We have measured protein kinetics in the scalded skin and normal muscle in anesthetized rabbits. On the 7th day after ear scald, L-[ring-13C6]phenylalanine was infused as a tracer, and the ear and hindlimb were used as arteriovenous units to reflect skin and muscle protein kinetics. Insulin was infused at 0.6 or 2.3-3.4 mU. kg-1. min-1 in the low-dose and high-dose insulin groups. In the growth hormone group, recombinant human growth hormone was administered at 2 mg. kg-1. day-1 after the ear was scalded. The results were compared with a control group in which the ear was scalded but otherwise was not treated. In the control group, net protein loss in the scalded skin and muscle was 23.1 +/- 21.4 and 3.9 +/- 1.5 micromol. 100 g-1. h-1, respectively. Insulin infusion at either high or low dose reduced net protein loss to near zero by inhibiting proteolysis. In contrast, growth hormone treatment had no anabolic effect on either tissue. In conclusion, insulin but not growth hormone has an anabolic effect on scalded skin and normal muscle; low-dose insulin is as effective in achieving an anabolic effect on both tissues, with less hypoglycemic response than high-dose insulin.
The American journal of physiology 05/1999; 276(4 Pt 1):E712-20.
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ABSTRACT: To investigate the hypothesis that a submaximal insulin dose reverses the net muscle catabolism associated with severe burns, and to determine its effects on amino acid kinetics.
The authors previously showed that a maximal dose of insulin administered to patients with severe burns promoted skeletal muscle glucose uptake and net protein synthesis. However, this treatment was associated with caloric overload resulting from the large quantities of exogenous glucose required to maintain euglycemia, and hypoglycemia was a potential problem.
Thirteen patients were studied after severe burn injury (>60% total body surface area). Patients were randomly treated by standard care (n = 5) or with exogenous insulin (n = 8). Data were derived from an arteriovenous model with primed-continuous infusions of stable isotopes and biopsies of the vastus lateralis muscle.
Net amino acid balance was significantly improved with insulin treatment. Skeletal muscle protein synthesis was significantly greater in the group receiving insulin, whereas muscle protein breakdown was not different between the groups. This submaximal dose of insulin did not affect glucose or amino acid uptake or require a greater caloric intake to avoid hypoglycemia.
Submaximal insulin can promote muscle anabolism without eliciting a hypoglycemic response.
Annals of Surgery 02/1999; 229(1):11-8. · 7.49 Impact Factor
