Nutritional status and plasma amino acid levels in hemodialysis

: The objective of this work is to study the relation between the variations of the plasmatic aminogram, and the nutritional state of the patient with chronic kidney failure on hemodialysis. We studied 79 patients with chronic kidney failure undergoing hemodialysis treatment, with and evolution of 46 +/- 37 months. They were subjected to a dietary questionnaire, and anthropometric study after dialysis (body mass index, triceps skin fold, muscular circumference of the arm), and determination of the levels of serum amino acids after a pre-dialysis nocturnal fast half way through the week, and finally a record is made of the number of times each patient was hospitalized in the 6 months prior to the study. In the amino acids with a pyruvate origin, there is a significant reduction of alanine (p: 0.002), serine (p: 0.004), and methionine (p: 0.001), and a significant increase of glycine, cystathionine, and cystine (p: 0.0001), with the Glycine/Serine coefficient being elevated (p: 0.001). All amino acids with a ketoglutarate origin are increased significantly (p < 0.007), except glutamine which is decreased (p: 0.0009), and arginine which does not show any significant differences. The essential amino acids are decreased in relation to the non-essential ones (p: 0.0001), although if they are compared with the normal values, only threonine is decreased (p: 0.001). Of the rest, histidine, isoleucine (p: 0.0001) and phenylalanine (p: 0.001) are significantly increased. The tyrosine/phenylalanine coefficient is decreased (p: 0.001). The daily ingestion of protein is correlated negatively with alanine, proline, hydroxyproline, and aspartic acid. The anthropometric parameters are correlated positively with the branched amino acids, alanine and proline. Finally, the number of hospital admissions in the last 6 months, is correlated positively with valine, leucine, phenylalanine, and glutamic acid. In conclusion, we consider that the increase of the glycine/serine, phenylalanine/serine and non essential/essential coefficients, is related to alterations of the metabolism, intrinsic to the condition of uremia, while the alterations of the levels of branched amino acids is related to the nutritional condition of the patients.