ESSENTIAL FATTY-ACID STATUS IN PATIENTS ON LONG-TERM HOME PARENTERAL-NUTRITION

Background: Patients on total parenteral nutrition are known to be at risk of the development of essential fatty acid deficiency, presenting as a syndrome with scaly skin lesions and characterized by low plasma and erythrocyte linoleic acid concentrations. The essential fatty aci d status of patients on long-term home parenteral nutrition who do hav e access to oral feeds has not been studied. Methods: With the use of an isocratic high-performance liquid chromatography method, fatty acid s were measured in the erythrocytes and plasma of 25 nonfasting patien ts on long-term home parenteral nutrition and the findings compared wi th those of 46 hospital outpatients not on nutrition support and five laboratory staff. Results: Statistically significant differences in th e two groups were limited to the erythrocytes. Linoleic acid was signi ficantly lower (25.2 us 40.7 mu mol/10(6) red blood cells, p < .0001) and showed a significant correlation with triceps skinfold thickness ( r = .52, p = .013). Palmitoleic and oleic acids were higher in patient s than controls (10.8 us 8.4 mu mol/10(6) red blood cells, p = .009; 6 1.2 vs 51.7 mol/10(6) red blood cells, p = .003). Conclusions: Despite IV linoleic acid administration, patients on long-term home parentera l nutrition have low erythrocyte stores of this essential fatty acid. This appears to be related to their low body fat stores. We suggest th at they may be using much of the infused linoleic acid as an energy so urce and therefore are at risk of subclinical essential fatty acid def iciency.