Essential fatty acid deficiency in four adult patients during total parenteral nutrition.

Four undernourished adults (15%-37% below idealll body weight) received fat-free total parenteral nutrition for a period of 6 to 8 weeks. Chemical evidence of essential fatty acid deficiency (triene:tetraene ratio greater than 0.4) appeared in all patients during the first 3 weeks of treatment. Deficiency developed more rapidly in the two patients who were younger (ages 16 and 36) and more severely undernourished (26% and 37% below ideal body weight) than in the two older patients (62 and 76) who were less undernourished (15% and 16% below idea body weight). All patients continued to gain weight and maintain positive nitrogen balance throughout the course of total parenteral nutrition and developing essential fatty acid deficiency. Hepatomegaly and increased serum liver enzyme activities occurred in the two patients with evidence of the most severe essential fatty acid deficiency. Liver biopsy, in the cases with hepatomegaly, showed hepatocytes containing fat and what appeared to be enlarged, spherical mitochondria. There was no cellular infiltrate or significant degree of necrosis. Supplementation with oral linoleic acid (as safflower oil) reversed the essential fatty acid deficiency and the elevation of serum liver enzymes.