Catabolism of chylomicron remnants in patients with previous acute pancreatitis

A recent study reports that patients with previous acute pancreatitis commonly have an abnormal clearance of serum triglycerides after an oral fat load. This observation supports the hypothesis that patients with previous acute pancreatitis and normal fasting serum triglyceride levels may have a preexistent abnormality in the metabolism of chylomicrons. To test this hypothesis, the catabolism of chylomicrons and their remnants was studied in a series of 7 patients who had sustained an attack of pancreatitis (2, gallstone related; 2, alcohol ingestion; 1, hydatid cyst; and 3, no associated pathological condition) at least 18 mo earlier. All the patients had previously had abnormal oral-fat tolerance test results. These patients were compared with a series of 6 healthy volunteers. Chylomicrons were endogenously labeled with an oral dose of retinyl palmitate, and their plasma elimination half-life was calculated. The retinyl palmitate absorption rate constants were similar in control and pancreatitis patients. The chylomicron t1/2 were 2.3 +/- 0.8 (SD) h and 3.9 +/- 1.8 h in the control and pancreatitis groups, respectively (p = 0.07). The chylomicron remnant t1/2 was 2.7 +/- 1.1 h in the control group and 5.2 +/- 2.4 h in the pancreatitis group (p less than 0.05). This study supports the hypothesis that subjects with previous acute pancreatitis may have an abnormality in the catabolism of chylomicron particles. This abnormality may represent a preexistent genetic condition expressed in either the apoprotein composition of chylomicrons or in the hepatic apolipoprotein E-receptor activity.