Response of albumin synthesis to oral nutrients in young and elderly subjects

Abstract

Background:The synthesis of albumin after oral ingestion of nutrients provides a means of storing amino acids, which can be made available during periods of fasting. Objective: This study was undertaken to see whether the response of albumin synthesis to the oral intake of nutrients is compromised in elderly subjects. Design: Albumin synthesis was determined from the incorporation of 43 mg L-[ 2 H 5 ]phenylalanine/kg body wt. Eight elderly subjects (aged 60 y) and 8 young subjects (aged 21-35 y) were studied on 3 separate occasions: after the intake of water, a liquid meal (with 15% of energy from protein, 30% of energy from fat, and 55% of energy from carbohydrate), or an isonitrogenous but not isocaloric meal containing only protein.Results: Mean (ȀSEM) albumin synthesis, expressed as an absolute rate (ie, the amount of albumin synthesized per day), was significantly lower in elderly subjects (108 Ȁ 7 mg ⅐ kg body wt Ҁ1 ⅐ d Ҁ1 ) than in young subjects (141 Ȁ 7 mg ⅐ kg body wt Ҁ1 ⅐ d Ҁ1 ). In response to the complete meal, albumin synthesis was significantly increased in both the elderly (144 Ȁ 7 mg ⅐ kg body wt Ҁ1 ⅐ d Ҁ1 ) and the young (187 Ȁ 11 mg ⅐ kg body wt Ҁ1 ⅐ d Ҁ1 ) subjects. The protein component of the meal was sufficient to stimulate albumin synthesis in both the elderly (147 Ȁ 14 mg ⅐ kg body wt Ҁ1 ⅐ d Ҁ1 ) and the young (182 Ȁ 6 mg ⅐ kg body wt Ҁ1 ⅐ d Ҁ1 ) subjects. Conclusions: Elderly subjects have lower rates of albumin synthesis than do young subjects during fasting, but they stimulate albumin synthesis proportionately in response to the oral ingestion of protein.

A Novel Amino Acids Oral Supplementation in Hemodialysis Patients: a Pilot Study

“…22 Accordingly, as underlined by Layman, the adequacy of proteins in efficiently supplying nitrogen is related primarily to the amount of EAs provided by them. Therefore, nitrogen supply should not be calculated as the total nitrogen content that is the sum of EAs plus NEAs, but mainly the adequacy of EAs intake.…”

Influence of Age and Nutritional Status on Glycated Albumin Values in Hemodialysis Patients

“…Some studies have shown a reduced rate of albumin synthesis in healthy elderly subjects (21 (23). The correlations between inflammatory markers, nutritional markers, and recombinant human erythropoietin (rHuEPO) doses were shown in the previous study (24).…”

Dynamics of Albumin Synthetic Response to Intra-Abdominal Abscess in Patients with Gastrointestinal Fistula

“…Albumin synthesis, which depends on the availability of intracellular amino acids, is well known to be influenced by the nutritional state [31]. Starvation and protein-deficient diets were associated with increased whole body protein kinetics and reduced albumin synthesis in vivo [32,33], whereas the progressive restoration of food intake was associated with a progressive increase in albumin synthesis [8].…”