Lipoprotein lipase expression in livers of morbidly obese patients could be responsible for liver steatosis.
BACKGROUND
Most patients with morbid obesity develop non-alcoholic fatty liver disease (NAFLD). The origins of lipid deposition in the liver and the effects of bariatric surgery in the obese with NAFLD are controversial.


METHODS
We analyzed lipids and lipoprotein lipase (LPL) in both plasma and liver biopsies performed before and 12-18 months after Roux-en-Y gastric bypass surgery in 26 patients.


RESULTS
In the livers of morbidly obese patients, the levels of LPL messenger RNA (mRNA) were higher (4.5-fold) before surgery than afterwards than control livers. In these patients, LPL activity was also significantly higher (91 +/- 7 mU/g) than in controls (51 +/- 3 mU/g, p = 0.0026) and correlated with the severity of the liver damage. All hepatic lipids were significantly increased in obese patients; however, after bariatric surgery, these lipids, with the exception of NEFA, tended to recover to normal levels.


CONCLUSIONS
The liver of obese patients presented higher LPL activity than controls, and unlike the controls, this enzyme could be synthesized in the liver because it also present LPL mRNA. The presence of the LPL activity could enable the liver to capture circulating triacylglycerides, thus favoring the typical steatosis observed in these patients.
Pardina
Eva
E
Biochemistry and Molecular Biology Department, Biology Faculty, Barcelona University, Diagonal 645, 08028, Barcelona, Spain.
Baena-Fustegueras
Juan A
JA
Llamas
Rafael
R
Catalán
Roberto
R
Galard
Rosa
R
Lecube
Albert
A
Fort
Jose M
JM
Llobera
Miquel
M
Allende
Helena
H
Vargas
Víctor
V
Peinado-Onsurbe
Julia
J
D000328:Adult; D015992:Body Mass Index; D016022:Case-Control Studies; D015331:Cohort Studies; D005234:Fatty Liver / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D005260:Female; D015390:Gastric Bypass; D006801:Humans; D008055:Lipids / Q000097:blood; D008071:Lipoprotein Lipase / Q000235:genetics / Q000378:metabolism*; D008099:Liver / Q000201:enzymology*; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000150:complications* / Q000201:enzymology* / Q000601:surgery; D012333:RNA, Messenger / Q000378:metabolism
D008055:Lipids; D012333:RNA, Messenger; D008071:Lipoprotein Lipase