Low- and high-density lipoprotein subclasses in subjects with nonalcoholic fatty liver disease

Abstract

Background: Nonalcoholic fatty liver disease (NAFLD) is associated with increased cardiometabolic risk. Although dyslipidemia represents a key factor in this disease, its impact on serum levels of distinct lipoprotein subfractions is largely unknown.

Objective: To assess the full low-density lipoprotein (LDL) and high-density lipoprotein (HDL) profiles in patients with NAFLD.

Methods: Seven LDL and 10 HDL subfractions were assessed by gel electrophoresis (Lipoprint, Quantimetrix Corporation, USA) in men with biopsy proven NAFLD (simple steatosis [n = 17, age, 34 ± 7 years] and nonalcoholic steatohepatitis [NASH; n = 24, age, 32 ± 6 years]). Exclusion criteria included robust alcohol consumption, infection with hepatitis B or C virus, body mass index ≥ 40 kg/m(2), diabetes mellitus, and hypertension.

Results: Compared with simple steatosis, NASH patients had similar body mass index, homeostasis model assessment of insulin resistance index and plasma lipids, with increased levels of both aspartate aminotransferase and alanine transaminase. NASH subjects had lower levels of larger LDL1 (10 ± 4 vs 13 ± 4%, P = .010) and increased smaller LDL3 and LDL4 particles (9 ± 5 vs 5 ± 5%, P = .017 and 3 ± 3 vs 1 ± 2%, P = .012, respectively). No changes were found in the HDL subclass profile. By multiple regression analysis, we found that NASH was associated only with increased levels of LDL3 (P = .0470).

Conclusions: The increased levels of small, dense LDL3 and LDL4 in NASH may help to at least partly explain the increased risk for atherosclerosis and cardiovascular diseases in these patients.

Keywords: Lipids; Lipoproteins; Nonalcoholic fatty liver disease; Nonalcoholic steatohepatitis; Simple steatosis.