Milan A M, D'Souza R F, Pundir S, Pileggi C A, Thorstensen E B, Barnett M P G, Markworth J F, Cameron-Smith D, Mitchell C J
Cameron Mitchell, The Liggins Institute, University of Auckland, 85 Park Road, Grafton, Private Bag 92019, Auckland 1023, New Zealand. Tel: +64 (09) 9236606, Fax: (+64 9) 373 7039, Email:
J Nutr Health Aging. 2015 Oct;19(8):839-45. doi: 10.1007/s12603-015-0500-5.
To measure the postprandial plasma amino acid appearance in younger and older adults following a high protein mixed meal.
Cross-sectional study.
Clinical research setting.
Healthy men and women aged 60-75 (n=15) years, and young controls aged 20-25 years (n=15) matched for body mass index and insulin sensitivity based on the homeostatic model assessment of insulin resistance.
High protein mixed meal of complete food products.
Circulating amino acid concentrations were determined hourly before and for 5 hours after meal ingestion.
There was no difference between cohorts in postprandial appearance of non-essential amino acids, or area under the curve of any individual amino acid or amino acid class. However, older adults had higher baseline concentrations of aspartic acid, glutamic acid, glycine, ornithine, threonine and tyrosine and lower baseline concentrations of hydroxyproline, isoleucine, leucine, methionine and valine compared to younger adults. Younger adults showed peak essential (EAA) and branched-chain amino acid (BCAA) concentrations at 1 hour post meal while older adults' peak EAA and BCAA concentration was at 3 hours. Similarly, peak total amino acid concentrations were at 3 hours in older adults.
Older adults digested and absorbed the protein within a mixed meal more slowly than younger adults. Delayed absorption of AA following a mixed meal of complete food products may suppress or delay protein synthesis in senescent muscle.
测量年轻和老年成年人在摄入高蛋白混合餐后餐后血浆氨基酸的出现情况。
横断面研究。
临床研究环境。
60 - 75岁的健康男性和女性（n = 15），以及20 - 25岁的年轻对照组（n = 15），根据胰岛素抵抗的稳态模型评估，在体重指数和胰岛素敏感性方面进行匹配。
完整食品的高蛋白混合餐。
在进餐前及进餐后5小时每小时测定循环氨基酸浓度。
在餐后非必需氨基酸的出现情况、任何单个氨基酸或氨基酸类别的曲线下面积方面，各队列之间没有差异。然而，与年轻成年人相比，老年人的天冬氨酸、谷氨酸、甘氨酸、鸟氨酸、苏氨酸和酪氨酸的基线浓度较高，而羟脯氨酸、异亮氨酸、亮氨酸、蛋氨酸和缬氨酸的基线浓度较低。年轻成年人在餐后1小时显示必需氨基酸（EAA）和支链氨基酸（BCAA）浓度达到峰值，而老年人的EAA和BCAA峰值浓度出现在3小时。同样，老年人的总氨基酸峰值浓度在3小时出现。
老年人在混合餐中对蛋白质的消化和吸收比年轻人更慢。完整食品混合餐后氨基酸吸收延迟可能会抑制或延缓衰老肌肉中的蛋白质合成。
