Serum sphingomyelin levels are related to the clearance of postprandial remnant-like particles

Axel Schlitt,Mohammad R Hojjati,Hans Von Gizycki,Karl J Lackner,Stefan Blankenberg,Bernhard Schwaab,Juergen Meyer,Hans J Rupprecht,Xian-Cheng Jiang

doi:10.1194/jlr.c400011-jlr200

Abstract

It is known that sphingomyelin (SM) content is higher in apolipoprotein B-containing particles (BLps) than in high density lipoproteins and that BLp levels, including chylomicrons and their remnant particles, are positively related to atherosclerosis. To evaluate the relationship between serum SM and postprandial remnant particle levels, we determined SM, triglyceride (TG), and cholesterol levels in serum and in remnant-like particles (RLPs) before and 3, 5, 7, and 10 h after a high-fat meal in 31 healthy subjects. We found that serum SM, like serum TG, was increased to its maximum 3 h after fat loading and then gradually decreased to basal levels after 10 h. More important, we determined that SM and TG levels in RLPs were parallel. Serum SM was positively correlated with serum TG (P <0.001), RLP SM (P <0.001), RLP TG (P <0.001), and RLP cholesterol (P <0.001) levels. It is our conclusion that serum SM is a marker for the clearance of RLPs.

Highlights

It is known that sphingomyelin (SM) content is higher in apolipoprotein B-containing particles (BLps) than in high density lipoproteins and that BLp levels, including chylomicrons and their remnant particles, are positively related to atherosclerosis
We found that mean serum concentrations of TG, SM, remnant-like particle (RLP) cholesterol, RLP TG, and RLP SM were low at fasting
The differences between the fasting and 5 h points remained significant for serum TG, serum SM, RLP TG, and RLP SM

Summary

Introduction

It is known that sphingomyelin (SM) content is higher in apolipoprotein B-containing particles (BLps) than in high density lipoproteins and that BLp levels, including chylomicrons and their remnant particles, are positively related to atherosclerosis. In a case-control study (279 cases and 277 controls), we have previously shown that plasma SM levels are an independent risk factor for coronary artery disease and demonstrated a significant correlation with remnant cholesterol levels [8]. Based on these results, we hypothesized that SM could be a marker for the clearance of TRL remnants and that enrichment of SM on the remnants could be atherogenic. We investigated the following: 1) postprandial serum SM and remnant-like particle (RLP) SM levels after high-fat diet loading, and 2) a possible predictive value of serum SM for RLP metabolism. It has been suggested that retention of BLps on the subendothelial matrix and subsequent aggregation triggers

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Results

Conclusion