Increased expression and activity of hepatic lipase in the liver of morbidly obese adult patients in relation to lipid content.

Background: The types and sources of lipid deposition in the liver of most patients with morbid obesity, as well as the effects of bariatric surgery, are discussed.

Methods: In 26 patients with morbid obesity who underwent bariatric surgery, we analyzed different kinds of lipids and hepatic lipase (HL) from both plasma and liver biopsies performed 12-18 months after surgery.

Results: The HL activity and HL-mRNA in morbidly obese (MO) livers were high (258 +/- 17 mU/g, and 4.5-fold, respectively); after surgery, the activity decreased (137 +/- 15 mU/g, p < 0.001) but not the levels of HL-mRNA (4.3-fold). Plasma HL activity was also high (4.31 +/- 0.94 mU/mL plasma), and it decreased during weight loss (2.01 +/- 0.29 mU/mL, p < 0.01); moreover, it correlated (r = 0.3694, p < 0.05) with decreased liver HL activity. Adrenocorticotropic hormone in MO was higher (27 +/- 3 pg/mL) than after surgery (13 +/- 1 pg/mL, p < 0.001). All hepatic and plasma lipids were significantly increased in MO patients, but, after bariatric surgery, most of those parameters recovered or normalized. Liver HL activity correlated with total and esterified cholesterol (r = 0.4399, p < 0.001 and r = 0.4395, p < 0.01, respectively).

Conclusion: High HL in MO patients could allow for liver intake of cholesterol that could be re-exported to steroidogenic organs to synthesize steroidal hormones. A decrease of plasma HL during weight loss could be a good index for improvement of liver disease.