Decreased postprandial response to a fat meal in normotriglyceridemic men with hypoalphalipoproteinemia.

The plasma level of high density lipoprotein cholesterol (HDL-C) has been reported to be inversely correlated with the level of triglycerides (TGs) and the magnitude of postprandial lipemia because subjects with low HDL-C accompanying high TG levels often have an increased postprandial response to a fat load. However, information is limited regarding the postprandial response to a fat load in subjects with low HDL-C and normal fasting TG values (hypoalphalipoproteinemia [hypoalpha]). We administered an oral fat load (70 g/m2 of body surface area) to six subjects with hypoalpha and six aged-matched control subjects. Plasma levels of lipids and lipoproteins and the mass of triglyceride-rich lipoproteins (TRLs: Sf > 100 and Sf 20-100) were measured every 2 hours for 8 hours. The mass and chemical composition of Sf > 100 or Sf 20-100 TRLs were not different between the fasting groups; postprandial Sf > 100 but not Sf 20-100 TRLs (mean +/- SD) was significantly lower in subjects with hypoalpha (200.4 +/- 64.8 mg/dL versus 110.6 +/- 50.9 mg/dL; analysis of variance, F test, p = 0.04). In the hypoalpha subjects, the compositions of postprandial Sf > 100 TRLs were TG poor and cholesterol and phospholipid enriched (p < 0.001) while the Sf 20-100 TRLs were enriched in cholesterol and phospholipid but relatively protein depleted (p = 0.002).(ABSTRACT TRUNCATED AT 250 WORDS)