title: Diurnal and acute patterns of postprandial apolipoprotein B-48 in VLDL, IDL, and LDL from normolipidemic humans.
abstract: Smaller size particles of intestinal origin may be more relevant to atherosclerosis than larger particles because of easier transendothelial transport. We examined the diurnal pattern in response to low-fat high-carbohydrate meals and the effect of a single high-fat milkshake on apoB-48 in very light Sf degrees >400, light Sf degrees 60-400, and dense Sf degrees 20-60 VLDL, IDL, and LDL in 24 subjects (12 in each study). After the high-fat meal, apoB-48 concentrations peaked at 3 h for very light VLDL, 4 h for light VLDL, and 5 h for dense VLDL and IDL, suggesting a delipidation cascade. The diurnal pattern was characterized by a sharp increase in light and dense VLDL apoB-48 after breakfast, reaching the highest concentration 4-8h after breakfast. Less response was observed after lunch, dinner or snack, despite 75% of energy supplied by these meals. The proportion of apoB-48 in LDL in the fasting state ranged between 48 and 54%. LDL apoB-48 concentration decreased by 35% after the high-fat meal, and slowly recovered to near fasting concentrations after 10-12 h. In contrast, in the diurnal study, LDL apoB-48 concentration steady increased peaking 13 h after breakfast, followed by a sharp decrease. In sum, most intestinally synthesized apoB lipoproteins circulate in LDL, and are likely formed in the late postprandial period from larger VLDL-size particles. Although small apoB-48 lipoproteins may be atherogenic remnant particles, their very low concentration may diminish their clinical significance.
authors.affiliation: Department of Nutrition, Harvard School of Public Health, 665 Huntington Avenue, Room 1-201, Boston, MA 02115, USA. hcampos@hsph.harvard.edu
authors.forename: Hannia
authors.initials: H
authors.lastname: Campos
authors.forename: Christina
authors.initials: C
authors.lastname: Khoo
authors.forename: Frank M
authors.initials: FM
authors.lastname: Sacks
mesh_terms: D000368:Aged; D053299:Apolipoprotein B-100; D053283:Apolipoprotein B-48; D001055:Apolipoproteins B / Q000097:blood* / Q000737:chemistry; D002784:Cholesterol / Q000097:blood* / Q000737:chemistry; D008078:Cholesterol, LDL / Q000097:blood / Q000737:chemistry; D015243:Cholesterol, VLDL / Q000097:blood / Q000737:chemistry; D002940:Circadian Rhythm / Q000502:physiology*; D004040:Dietary Carbohydrates / Q000097:blood / Q000493:pharmacokinetics; D005260:Female; D006801:Humans; D008074:Lipoproteins / Q000097:blood / Q000737:chemistry; D008875:Middle Aged; D010316:Particle Size; D019518:Postprandial Period / Q000502:physiology; D012016:Reference Values
chemical_list: D053299:Apolipoprotein B-100; D053283:Apolipoprotein B-48; D001055:Apolipoproteins B; D008078:Cholesterol, LDL; D015243:Cholesterol, VLDL; D004040:Dietary Carbohydrates; D008074:Lipoproteins; C030104:lipoprotein cholesterol; D002784:Cholesterol