title: Older adults have an altered chylomicron response to a high-fat meal.
abstract: 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.
authors.affiliation: 1Liggins Institute,University of Auckland,85 Park Road,Grafton,Private Bag 92019,Auckland 1023,New Zealand.
authors.forename: Amber M
authors.initials: AM
authors.lastname: Milan
authors.affiliation: 2Food Chemistry and Food Development,Department of Biochemistry,University of Turku,Vatselankatu 2,FI-20014 Turku,Finland.
authors.forename: Anu
authors.initials: A
authors.lastname: Nuora
authors.affiliation: 1Liggins Institute,University of Auckland,85 Park Road,Grafton,Private Bag 92019,Auckland 1023,New Zealand.
authors.forename: Shikha
authors.initials: S
authors.lastname: Pundir
authors.affiliation: 1Liggins Institute,University of Auckland,85 Park Road,Grafton,Private Bag 92019,Auckland 1023,New Zealand.
authors.forename: Chantal A
authors.initials: CA
authors.lastname: Pileggi
authors.affiliation: 1Liggins Institute,University of Auckland,85 Park Road,Grafton,Private Bag 92019,Auckland 1023,New Zealand.
authors.forename: James F
authors.initials: JF
authors.lastname: Markworth
authors.affiliation: 2Food Chemistry and Food Development,Department of Biochemistry,University of Turku,Vatselankatu 2,FI-20014 Turku,Finland.
authors.forename: Kaisa M
authors.initials: KM
authors.lastname: Linderborg
authors.affiliation: 1Liggins Institute,University of Auckland,85 Park Road,Grafton,Private Bag 92019,Auckland 1023,New Zealand.
authors.forename: David
authors.initials: D
authors.lastname: Cameron-Smith
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D001055:Apolipoproteins B / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D002914:Chylomicrons / Q000097:blood*; D003430:Cross-Sectional Studies; D059305:Diet, High-Fat; D004041:Dietary Fats / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D006949:Hyperlipidemias / Q000097:blood; D007328:Insulin / Q000097:blood; D008297:Male; D062407:Meals; D008875:Middle Aged; D019301:Oleic Acid / Q000097:blood; D010316:Particle Size; D019518:Postprandial Period; D014280:Triglycerides / Q000097:blood; D055815:Young Adult
chemical_list: D001055:Apolipoproteins B; D001786:Blood Glucose; D002914:Chylomicrons; D004041:Dietary Fats; D007328:Insulin; D014280:Triglycerides; D019301:Oleic Acid
keywords: CMRF chylomicron-rich fraction; Cholesterol; Diet and dietary lipids; Lipidomics; Lipoproteins; Nutrition; PL phospholipid; Phospholipids; TAG; TRL TAG-rich lipoproteins