Post-prandial chylomicron response may be predicted by a single measurement of plasma apolipoprotein B48 in the fasting state

Background The clearance of chylomicron remnants was assessed in normolipae mic, dyslipidaemic and obese male subjects by monitoring the plasma kinetic s of apolipoprotein (apo) B48, retinyl palmitate and triglyceride after a l ipid meal. Regression analysis of fasting plasma apo B48 with the area unde r the post-prandial curves of apo B48, retinyl ester and triglyceride was c arried out in order to determine whether the post-prandial response could b e predicted by the fasting concentration of this exclusive chylomicron mark er. Materials and methods Fasted subjects were given an oral fat load supplemen ted with retinyl palmitate, and blood samples were drawn over a 10-h period . Apolipoprotein B48 was determined by Western blotting in the plasma densi ty fraction less than 1.063 gmL(-1) Plasma retinyl palmitate and triglyceri de were determined by high-performance liquid chromatography (HPLC) and col orimetric procedures respectively. The areas under the apo B48, retinyl est er and triglyceride curves were determined by integration. Relationships be tween the post-prandial response and the fasting concentration of apolipopr otein B48 were assessed using least-squares regression analysis. Results We found a strong positive relationship between the fasting plasma concentration of apo B48 and the post-prandial kinetics of apo B48. Similar ly, there was a positive relationship of fasting apo B48 with the retinyl e ster area under the curve. Collectively, the data suggested that chylomicro n remnant kinetics can be predicted based on the fasting level of apo B48. There was also a significant but weaker relationship of fasting apo B48 wit h postprandial triglyceride kinetics, consistent with removal of this lipid by hydrolytic mechanisms in addition to particle uptake. Conclusion The fasting plasma concentration of apo B48 appeared to be a goo d surrogate marker for the degree of post-prandial lipidaemia and may circu mvent the need for oral fat challenges. Moreover, in the fasting state apo B48 concentration is a marker of chylomicron remnants, which are considered to be the proatherogenic form of these intestinally derived lipoproteins.