Abstract
Postabsorptive plasma concentrations of the large neutral amino acids (LNAAs) were measured in 74 elderly (age 71 ± 8 y) and 138 young (age 26 ± 5 y) healthy subjects. Plasma concentrations of valine, leucine, and isoleucine were significantly lower in young females than in young males. This gender-related difference was not observed among elderly subjects because aging was associated with a significant rise in plasma LNAAs in females but not in males. Multiple-regression analysis of plasma amino acid concentrations from female subjects revealed a significant and positive effect of age on plasma valine, leucine, isoleucine, phenylalanine, and tyrosine but not on plasma tryptophan or methionine. Tryptophan was the only amino acid to exhibit a significant response to age in males, consisting of a 14% decline in the elderly subjects. Percentile ranges are presented for young and elderly females and males for each of the amino acids.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1249-1252 |
| Number of pages | 4 |
| Journal | American Journal of Clinical Nutrition |
| Volume | 53 |
| Issue number | 5 |
| DOIs | |
| State | Published - 1991 |
Keywords
- Aging
- Normal values
- Plasma amino acids
ASJC Scopus subject areas
- Medicine (miscellaneous)
- Nutrition and Dietetics