FATTY-ACID POOL SIZE IN PLASMA-LIPOPROTEIN FRACTIONS OF CYSTIC-FIBROSIS PATIENTS

The objective of this study was to quantitatively measure the essential fatty acid pools in lipid fractions of plasma lipoproteins and the alteration of these pool sizes after consumption of a physiologic intake of fish oil. Twenty-three cystic fibrosis (CF) patients and 21 normal subjects were supplemented with fish oil, providing 35 mg n-3 fatty acids/kg body wt for 4 wk. Blood was collected pre- and postsupplementation and was quantitatively analyzed to determine the fatty acid pool size in each lipid class of low-density lipoproteins (LDLs), high-density lipoproteins (HDLs), and very-low-density lipoproteins. Two 7-d food records were collected to determine total fat and fatty acid intakes. Intakes of protein, carbohydrate, and fat as a percentage of energy and the ratio of polyunsaturated to saturated fats was similar for the CF and control groups. Energy intake was greater for CF subjects. Smaller lipoprotein essential fatty acid pools were observed in CF patients than in control subjects. Healthy subjects had larger essential fatty acid pool sizes in cholesterol ester fractions of HDLs and LDLs than CF subjects. Cholesterol ester and phosphatidylcholine pools transported the majority of essential fatty acids in both CF and control subjects.