Diagnosis of lipid malabsorption in patients with chronic pancreatitis: a new indirect test using postprandial plasma apolipoprotein B-48.

Abstract

This study was done to evaluate a new test for fat malabsorption caused by chronic pancreatitis. Postprandial plasma apolipoprotein B-48 was measured as an indicator of the intestinal assimilation of exogenous lipid. Twenty-three patients with chronic pancreatitis, including 19 insulin-treated diabetic patients, were compared with 14 healthy subjects and seven type-1 diabetic patients. Each was given a test meal containing 40 g lipid; the triglyceride apolipoprotein B-48 concentrations in chylomicrons were determined 240 min later. The postprandial chylomicron apolipoprotein B-48 concentrations in the three groups were statistically different at 240 min: pancreatitis versus controls, p < 0.01, and pancreatitis versus type-1 diabetes subjects, p < 0.01. The delta plasma apo B-48, the change in apolipoprotein B-48 between 0 and 240 min, was significantly smaller in chronic pancreatitis patients than in controls (p < 0.001) and type-1 diabetes subjects (p < 0.001). The sensitivity of the test was better than 89% for a delta apo B-48 threshold value of 0.42 mg/dl. This new indirect test is relatively simple to use and could be practical for evaluating exogenous lipid malabsorption due to chronic pancreatitis.