Relationships between pulmonary function and plasma fatty acid levels in cystic fibrosis patients.

Nineteen patients with cystic fibrosis (CF) were studied to determine whether plasma fatty acids correlated with severity of their lung disease as assessed by pulmonary function testing. Results were compared with 19 normal subjects of similar age and sex. Linoleic acid content of all lipid fractions was significantly lower in CF patients than controls including cholesterol ester fraction (CF 31%, control 50%, p less than 0.001), triglyceride fraction (7.6 to 16.6%, p less than 0.001), and phospholipid fraction (13.9 to 21.7%, p less than 0.001). Mean 20:3 omega 9/20:4 omega 6 ratio for CF patients was higher in all lipid classes and was suggestive of essential fatty acid deficiency. Correlations were found to exist between most pulmonary function parameters and fatty acids of plasma phospholipids but not any other lipid class. Positive correlations were found between all ventilatory tests and total omega 3 polyunsaturated fatty acids and also 22:5 omega 3 and 22:6 omega 3. There was no correlation between total saturated fatty acids, total monounsaturates, total omega 6 fatty acids, or triene/tetraene ratios and pulmonary function. Positive correlations were found between pulmonary function parameters and certain omega 6 polyunsaturates including 20:4 and 22:4 but not 18:2.