The relative importance of the usual diet in serum
phospholipids in subjects with
cystic fibrosis (CF) has been poorly studied. To compare the
fatty acid profile in serum
phospholipids from adult CF subjects with that of healthy subjects, and determine the role of the normal diet in this profile, we studied thirty-seven adult CF subjects with stable
pulmonary disease and thirty-seven healthy controls matched for age, sex and nutritional status. A dietary questionnaire was obtained, anthropometric data were recorded, and the
fatty acid profile measured by GLC. Compared with the controls, the percentages of myristic, palmitoleic and
stearic acids and total MUFA were significantly higher in the CF group, and DHA,
linoleic acid, total PUFA and
n-6 fatty acids were significantly lower in the CF group. The CF subjects with worse pulmonary function and with
pancreatic insufficiency had significantly lower levels of linoleic and
n-6 fatty acids. The total energy intake was significantly higher in the CF subjects, although the energy distribution in the CF subjects and the controls was not different for the
carbohydrates,
lipids and
proteins. No differences were detected in fat intake for MUFA (51 (SD 4) v. 52 (SD 4) %) or
saturated fatty acids (33.5 (SD 5) v. 31.2 (SD 3.8) %), but the PUFA were slightly lower in the CF subjects (15.4 (SD 4.5) v. 17.4 (SD 4.2) %; P=0.02). The usual dietary intake of
fatty acids by adult CF subjects does not appear to explain the difference in the
fatty acid profile compared with controls. This suggests an abnormal
fatty acid metabolism in CF subjects.