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 acid status of patients on long-term home parenteral nutrition who do have access to oral feeds has not been studied. Methods: With the use of an isocratic high-performance liquid chromatography method, fatty acids were measured in the erythrocytes and plasma of 25 nonfasting patients on long-term home parenteral nutrition and the findings compared with those of 46 hospital outpatients not on nutrition support and five laboratory staff. Results: Statistically significant differences in the two groups were limited to the erythrocytes. Linoleic acid was significantly 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 patients than controls (10.8 us 8.4 mu mol/10(6) red blood cells, p = .009; 61.2 vs 51.7 mol/10(6) red blood cells, p = .003). Conclusions: Despite IV linoleic acid administration, patients on long-term home parenteral nutrition have low erythrocyte stores of this essential fatty acid. This appears to be related to their low body fat stores. We suggest that they may be using much of the infused linoleic acid as an energy source and therefore are at risk of subclinical essential fatty acid deficiency.