Milan Amber M, Nuora Anu, Pundir Shikha, Pileggi Chantal A, Markworth James F, Linderborg Kaisa M, Cameron-Smith David
1Liggins Institute,University of Auckland,85 Park Road,Grafton,Private Bag 92019,Auckland 1023,New Zealand.
2Food Chemistry and Food Development,Department of Biochemistry,University of Turku,Vatselankatu 2,FI-20014 Turku,Finland.
Br J Nutr. 2016 Mar 14;115(5):791-9. doi: 10.1017/S000711451500505X. Epub 2016 Jan 15.
Ageing is associated with a prolonged and exaggerated postprandial lipaemia. This study aimed to examine the contribution of alterations in chylomicron synthesis, size and lipid composition to increased lipaemia. Healthy older (60-75 years; n 15) and younger (20-25 years; n 15) subjects consumed a high-fat breakfast. Chylomicron dynamics and fatty acid composition were analysed for 5 h in the postprandial state. Plasma TAG levels were elevated following the meal in the older subjects, relative to younger subjects (P<0·01). For older subjects compared with younger subjects, circulating chylomicron particle size was smaller (P<0·05), with greater apoB content (P<0·05) at all postprandial time points. However, total chylomicron TAG concentration between the groups was unaltered post-meal. Compared with younger subjects, the older subjects exhibited a greater proportion of oleic acid in the TAG and phospholipid (PL) fraction (P<0·05), plus lower proportions of linoleic acid in the TAG fraction of the chylomicrons (P<0·01). Thus, following the ingestion of a high-fat meal, older individuals demonstrate both smaller, more numerous chylomicrons, with a greater total MUFA and lower PUFA contents. These data suggest that the increased postprandial lipaemia of ageing cannot be attributed to increased chylomicron TAG. Rather, ageing is associated with changes in chylomicron particle size, apoB content and fatty acid composition of the chylomicron TAG and PL fractions.
衰老与餐后血脂异常的持续时间延长和程度加重有关。本研究旨在探讨乳糜微粒合成、大小和脂质组成的改变对血脂升高的影响。健康的老年（60 - 75岁；n = 15）和年轻（20 - 25岁；n = 15）受试者食用了高脂早餐。在餐后状态下分析乳糜微粒动力学和脂肪酸组成5小时。与年轻受试者相比，老年受试者餐后血浆甘油三酯（TAG）水平升高（P<0·01）。与年轻受试者相比，老年受试者在所有餐后时间点循环乳糜微粒粒径较小（P<0·05），载脂蛋白B（apoB）含量更高（P<0·05）。然而，餐后两组之间乳糜微粒总TAG浓度未改变。与年轻受试者相比，老年受试者乳糜微粒TAG和磷脂（PL）部分中油酸比例更高（P<0·05），而乳糜微粒TAG部分中亚油酸比例更低（P<0·01）。因此，摄入高脂餐后，老年人的乳糜微粒更小、数量更多，总单不饱和脂肪酸（MUFA）含量更高，多不饱和脂肪酸（PUFA）含量更低。这些数据表明，衰老导致的餐后血脂升高不能归因于乳糜微粒TAG增加。相反，衰老与乳糜微粒粒径、apoB含量以及乳糜微粒TAG和PL部分的脂肪酸组成变化有关。
