Dietary fat and physiological determinants of plasma chylomicron remnant homoeostasis in normolipidaemic subjects: insight into atherogenic risk

Abstract

TAG depleted remnants of postprandial chylomicrons are a risk factor for atherosclerosis. Recent studies have demonstrated that in the fasted state, the majority of chylomicrons are small enough for transcytosis to arterial subendothelial space and accelerate atherogenesis. However, the size distribution of chylomicrons in the absorptive state is unclear. This study explored in normolipidaemic subjects the postprandial distribution of the chylomicron marker, apoB-48, in a TAG-rich lipoprotein plasma fraction (Svedberg flotation rate (Sf>400), in partially hydrolysed remnants (Sf 20-400) and in a TAG-deplete fraction (Sf<20), following ingestion of isoenergetic meals with either palm oil (PO), rice bran or coconut oil. Results from this study show that the majority of fasting chylomicrons are within the potentially pro-atherogenic Sf<20 fraction (70-75 %). Following the ingestion of test meals, chylomicronaemia was also principally distributed within the Sf<20 fraction. However, approximately 40 % of subjects demonstrated exaggerated postprandial lipaemia specifically in response to the SFA-rich PO meal, with a transient shift to more buoyant chylomicron fractions. The latter demonstrates that heterogeneity in the magnitude and duration of hyper-remnantaemia is dependent on both the nature of the meal fatty acids ingested and possible metabolic determinants that influence chylomicron metabolism. The study findings reiterate that fasting plasma TAG is a poor indicator of atherogenic chylomicron remnant homoeostasis and emphasises the merits of considering specifically, chylomicron remnant abundance and kinetics in the context of atherogenic risk. Few studies address the latter, despite the majority of life being spent in the postprandial and absorptive state.

Effects of Low-Fat and High-Fat Meals, with and without Dietary Fiber, on Postprandial Endothelial Function, Triglyceridemia, and Glycemia in Adolescents

“…Reduction in cardiovascular disease risk has been associated with fiber intake [30]. This positive outcome of dietary fiber consumption may, in part, be related to the attenuation of triglycerides in the postprandial state, a period important in the development of coronary artery disease [2,3]. Atherosclerosis may begin as early as childhood and adolescence [8,9].…”

“…Endothelial dysfunction is an underlying issue associated with cardiovascular disease risk, that directly relates to the pathogenesis of atherosclerosis [1]. It is well documented that the postprandial period may be important in the development of coronary artery disease [2,3]. The transient increase in postprandial triglycerides and glucose may play a key role in this relationship, as non-fasting triglycerides [4] and glucose [5,6] have been reported to be significant predictors of coronary artery disease.…”

Rice Bran Derived Bioactive Compounds Modulate Risk Factors of Cardiovascular Disease and Type 2 Diabetes Mellitus: An Updated Review

“…In humans, when the effect of dietary supplementation of palm oil, RB oil and coconut oil was examined in normolipidaemic subjects, increased susceptibility to develop exaggerated chylomicron (small fat globules that transport lipids to tissues) remnantaemia were reported. This was in response to meals enriched in saturated fatty acids derived from a palm oil diet, thus contributing to increased atherogenic risk [48]. However, individuals consuming an RB or coconut oil diet did not develop atherogenic risk factors [48].…”

“…This was in response to meals enriched in saturated fatty acids derived from a palm oil diet, thus contributing to increased atherogenic risk [48]. However, individuals consuming an RB or coconut oil diet did not develop atherogenic risk factors [48]. In hyperlipidemic patients, an RB oil supplemented diet reduced weight, body mass index, waist and hip circumferences [49], total cholesterol, LDL and the atherogenic ratio of total cholesterol/HDL [49].…”

Addition of milk fat globule membrane-enriched supplement to a high-fat meal attenuates insulin secretion and induction of soluble epoxide hydrolase gene expression in the postprandial state in overweight and obese subjects

“…In Western societies, most of the day is spent in the postprandial period, with only a few hours in the early morning spent in the fasted state ( 14 – 16 ) . Risk for chronic metabolic disease may be more apparent by looking at the inflammatory response following a meal, as opposed to looking at fasting markers of inflammation ( 14 ) . Furthermore, meal composition is an important determinant of postprandial macronutrient metabolism and inflammation.…”