Mechanisms permitting nephrotic patients to achieve nitrogen equilibrium with a protein-restricted diet
| Autor: | K Tom, V. R. Young, C Staffeld, A Manatunga, B J Maroni |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
Adult
Male Nitrogen balance medicine.medical_specialty Nephrotic Syndrome Anabolism Nitrogen medicine.medical_treatment Protein degradation Biology Models Biological Low-protein diet Leucine Reference Values Internal medicine Diet Protein-Restricted medicine Humans Aged chemistry.chemical_classification Carbon Isotopes Protein turnover General Medicine Middle Aged Deuterium medicine.disease Amino acid Kinetics Proteinuria Endocrinology chemistry Female Nephrotic syndrome Mathematics Research Article |
| Zdroj: | Journal of Clinical Investigation. 99:2479-2487 |
| ISSN: | 0021-9738 |
| DOI: | 10.1172/jci119432 |
| Popis: | Clinical experience suggests nephrotic patients are at risk for malnutrition. To determine if nephrotic patients can adapt successfully to a protein-restricted diet, nephrotic (glomerular filtration rate, 52+/-15 ml/min; urinary protein [Uprot.], 7.2+/-2.2 grams/d) and control subjects completed a crossover comparison of diets providing 0.8 or 1.6 grams protein (plus 1 gram protein/gram Uprot.) and 35 kcal per kg per day. Nitrogen balance (BN) was determined and whole body protein turnover measured during fasting and feeding using intravenous -[1-13C]leucine and intragastric -[5,5, 5- 2H3]leucine. BN was positive in both nephrotic and control subjects consuming either diet and rates of whole-body protein synthesis, protein degradation, and leucine oxidation did not differ between groups. In both nephrotic and control subjects anabolism was due to a suppression of whole-body protein degradation and stimulation of protein synthesis during feeding. The principal compensatory response to dietary protein restriction was a decrease in amino acid oxidation and this response was the same in both groups. With the low protein diet leucine oxidation rates during feeding correlated inversely with Uprot. losses (r = -0.83; P < 0. 05). Conclusions: (a) a diet providing 0.8 gram protein (plus 1 gram protein/gram Uprot.) and 35 kcal per kg per day maintains BN in nephrotic patients; (b) nephrotic patients activate normal anabolic responses to dietary protein restriction (suppression of amino acid oxidation) and feeding (stimulation of protein synthesis and inhibition of protein degradation); (c) the inverse correlation between leucine oxidation and Uprot. losses suggests that proteinuria is a stimulus to conserve dietary essential amino acids. |
| Databáze: | OpenAIRE |
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