Absorption and transport of dietary long-chain fatty acids in cirrhosis: a stable-isotope-tracing study.
BACKGROUND
In rats, 30-70% of dietary fatty acids (FAs) are absorbed through the portal vein. Whether this occurs in humans is unknown, but it may occur in persons with cirrhosis, who show a blunted chylomicronemic response to dietary fat without significant steatorrhea.


OBJECTIVE
The objective was to investigate whether portal FA absorption occurs in humans with cirrhosis.


METHODS
Six control subjects and 10 patients with (n = 5) and without (n = 5) cirrhotic ascites were fed [1-(13)C]palmitic and oleic acids in a test meal. Samples were drawn before and 30, 60, 90, 120, 240, 360, 480, and 720 min afterward for plasma [1-(13)C]-labeled FAs and breath (13)CO(2) assay. Fecal [1-(13)C]-labeled FAs were also measured.


RESULTS
[1-(13)C]-Labeled FAs increased in chylomicrons in all groups, but less in ascitic cirrhotic patients, because their median area under the curve from 120 to 720 min was significantly lower than in the control subjects for labeled palmitate [520 (interquartile range: 192-1137) compared with 2862 (2674-4175) micromol . min/L] and oleate [829 (781-1263) compared with 3119 (2939-4986) micromol . min/L]. [1-(13)C]-Labeled FA enrichment of VLDL was also lower in cirrhotic patients. [1-(13)C]-Labeled FA in free FAs peaked earlier in ascitic than in nonascitic patients and control subjects, mainly for [1-(13)C]oleate, and the median area under the curve from 0 to 120 min was significantly higher in ascitic patients than in control subjects [301 (255-400) compared with 48 (34-185) micromol . min/L]. Fecal excretion of [1-(13)C]-labeled FA was negligible and not significantly different between groups.


CONCLUSIONS
The low [1-(13)C]-labeled FA concentrations in chylomicrons and VLDL, without increased fecal losses, confirm previous data in cirrhotic patients with the use of an unlabeled fat load. The earlier [1-(13)C]-labeled FA appearance in free FAs supports the portal absorption of dietary fat in patients with advanced cirrhosis with spontaneous portal-systemic shunting.
Cabré
Eduard
E
Department of Gastroenterology, Hospital Universitari Germans Trias i Pujol, Badalona, Catalonia, Spain.
Hernández-Pérez
José M
JM
Fluvià
Lourdes
L
Pastor
Cruz
C
Corominas
August
A
Gassull
Miquel A
MA
D000368:Aged; D019540:Area Under Curve; D001201:Ascites / Q000209:etiology / Q000378:metabolism*; D001944:Breath Tests; D002247:Carbon Isotopes; D016022:Case-Control Studies; D002914:Chylomicrons / Q000737:chemistry; D004041:Dietary Fats / Q000493:pharmacokinetics*; D005243:Feces / Q000737:chemistry; D005260:Female; D006801:Humans; D007408:Intestinal Absorption; D008103:Liver Cirrhosis / Q000150:complications / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D019301:Oleic Acid / Q000493:pharmacokinetics*; D019308:Palmitic Acid / Q000493:pharmacokinetics*; D011169:Portal Vein / Q000378:metabolism
D002247:Carbon Isotopes; D002914:Chylomicrons; D004041:Dietary Fats; D019301:Oleic Acid; D019308:Palmitic Acid