Plasma fatty acid composition in patients with ileal dysfunction.

Abstract

Chemical signs of essential fatty acid deficiency (EFD) were studied in 31 patients who has undergone an ileal resection on an average 7 years earlier by determining fatty acid composition in serum lipids. The subjects were divided into two groups in accordance with the presence (greater than 7 g/day) or absence (less than 7 g/day) of fat malabsorption. The two groups were matched for age, nutritional status, and essential fatty acid intake, but the patients with steatorrhea had higher levels of fecal bile acids and serum triglycerides and lower levels of serum cholesterol than those without steatorrhea. The contents of linoleic acid (LA; 18:2,n-6), the sum of n-6 polyunsaturated fatty acids, and eicosapentaenoic acid levels were lower, whereas those of the C 14-18 saturated and monoenoic fatty acids and eicosatrienoic fatty acid (ETA; 20:3,n-9), a characteristic fatty acid of EFD, were higher in the serum lipids of the patients with fat malabsorption. The LA of cholesterol esters, the ETA of phospholipids, and the ETA to arachidonic acid ratio of phospholipids were closely correlated with the amount of fecal fat, less significantly with the composition of dietary fat or the length of excluded intestine, and not at all with relative body weight or the amount of fecal bile acids. Changes in fatty acid patterns, considered characteristic of EFD, were found for almost a third of the patients with fat malabsorption; yet no clinical evidence of EFD was documented. Thus, the results demonstrate that chemical signs of EFD are common in patients with fat malabsorption after gut resections despite the good nutritional status. The findings suggest that, for preventive purposes, patients with gut resections should increase their dietary intake of polyunsaturated fatty acids in proportion to the amount of fecal fat.