To better define lipid transport in patients with hyperapobetalipoproteinemia (HyperapoB), the response to an oral fat load was studied in six normotriglyceridemic patients with the disorder. Plasma triglycerides; Sf > 400, and Sf 20 to 400 triglycerides; Sf > 20 B100; total HDL and HDL subfractions (HDL2 and HDL3) were measured serially for a 7-hour period after an oral fat load and changes in these parameters were compared to those observed in six normolipidemic controls. In addition, plasma triglyceride levels and HDL2 and HDL3 cholesterol were also determined in seven patients with Type IV hyperlipoproteinemia: three with normal LDL apo B levels and four with HyperapoB. When the two normotriglyceridemic groups were compared, the patients with HyperapoB had significantly higher fasting levels of SF > 400 lipoproteins and higher fasting VLDL and LDL levels than the normal patients. After the fat load, Sf 20 to 400 triglycerides and Sf > 20 B100 levels increased in both groups. Plasma triglycerides rose to a higher level in the HyperapoB patients than in the normal group, but more strikingly, remained elevated in the HyperapoB patients, an elevation due principally to a persistent increase in Sf > 400 triglycerides. On the other hand, HDL2 cholesterol dropped substantially in the HyperapoB patients but not in the normal patients. Finally, in the hypertriglyceridemic group, after the fat load, HDL2 cholesterol levels did not change in the patients with normal LDL apo B levels but did increase in those with elevated plasma LDL apo B.
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine