Hepatic lipase activity is increased in non- alcoholic fatty liver disease beyond insulin resistance

Abstract

Background and objective

Hepatic lipase (HL) is a lipolytic enzyme mostly synthesized and localized at the surface of liver sinusoidal capillaries which hydrolyses triglycerides and phospholipids of intermediate (IDL), large low density (LDL) and high density lipoproteins (HDL). HL activity is increased in insulin resistant states. Non-alcoholic fatty liver disease (NAFLD) is characterized by insulin resistance, however at present no data are available regarding the behavior of HL in reference to hepatic steatosis degree. Our aim was to evaluate HL activity in NAFLD patients and its relationship with the different hepatic steatosis grade.

Design and patients

We studied forty eight patients with NAFLD (diagnosed by ultrasonography and confirmed by liver biopsy) and thirty controls. Steatosis was semi quantitatively assessed and considered as mild or grade 1; moderate or grade 2 and severe or grade 3. Measurements: HL activity, lipid and lipoprotein profile (including IDL and dense LDL), adiponectin, insulin, glucose and high sensitivity C-reactive protein (hs-CRP) were measured. HOMA index (homeostasis model assessment for insulin resistance) was calculated.

Results

Patients with hepatic steatosis (HS) presented higher HL activity, HOMA and dense LDL and lower levels of adiponectin, HDL-cholesterol and apoAI. HL activity positively correlated and significantly with HS degree. HL correlated with a more atherogenic profile and persisted higher in patients even after corrected by age, gender, BMI, HOMA, and adiponectin.

Conclusion

The higher HL activity in NAFLD patients contributes to a more atherogenic profile linked to increased cardiovascular risk, beyond the insulin resistance and the reduction in adiponectin. Copyright © 2012 John Wiley & Sons, Ltd.