Dietary lysine requirements of older adults stratified by age and sex
Abstract
BACKGROUND
Current recommendation for lysine in older adults, 30 mg. kg-1.d-1, is based on young adult data. Evidence suggests that amino acid requirements may differ between young and old adults with both sex and age having an effect in the elderly OBJECTIVES: 1) Define the lysine requirements in healthy older adults using the indicator amino acid oxidation (IAAO) method with L-[1-13C]phenylalanine as the indicator and 2) compare the derived estimates based on age: 60-69y and >70y METHODS: Fourteen healthy males and 16 healthy females (> 60y, BMI=26.3 kg.m-2) were randomly assigned to receive 3 to 7 lysine intakes from 10 to 80 mg. kg-1. d-1. Subjects were adapted to a standard liquid diet providing 1.0 g. kg-1.d-1 protein and adequate energy, for 2 days, with indicator oxidation measurements performed on day three. The rate of release of 13CO2 from the oxidation of L-[1-13C] phenylalanine was measured in breath. A two-phase linear mixed effect model, and parametric bootstrap were used to determine mean lysine requirements and the 95% confidence intervals (CI). The overlap of the 95% CI between the 2 age groups were used to compare the requirement estimates. The null hypothesis was accepted if the interval contained zero RESULTS: The mean and upper 95% CI of the lysine requirement for females were 32.9 and 40.9, and 46.2 and 53.7 mg. kg-1.d-1 for those 60-69 and >70y, respectively. The mean and upper 95% CI of the lysine requirement for the 2 groups of males were not…
How strong is the evidence?
Evidence Hub reads this as a randomized trial, done in people. Its evidence level is 2 of 5 (High · randomized trial). Randomized trials of a reasonable size are the strongest single-study design.
Read the paper
Related studies
- Diagnosis and management of glutaric aciduria type I – revised recommendations
- EZH2 Codon 641 Mutations are Common in BCL2-Rearranged Germinal Center B Cell Lymphomas
- Consensus guidelines for the diagnosis and management of pyridoxine‐dependent epilepsy due to α‐aminoadipic semialdehyde dehydrogenase deficiency
- Systemic Metabolomic Changes in Blood Samples of Lung Cancer Patients Identified by Gas Chromatography Time-of-Flight Mass Spectrometry
- Human OTULIN haploinsufficiency impairs cell-intrinsic immunity to staphylococcal α-toxin
- Discovery of Novel Recurrent Mutations in Childhood Early T-Cell Precursor Acute Lymphoblastic Leukemia by Whole Genome Sequencing - a Report From the St Jude Children's Research Hospital - Washington University Pediatric Cancer Genome Project
Go deeper in Evidence Hub
Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.