Hepatic Steatosis and Insulin Resistance, But Not Steatohepatitis, Promote Atherogenic Dyslipidemia in NAFLD

Context: Patients with nonalcoholic fatty liver disease (NAFLD) are at increased risk of cardiovascular disease, and atherogenic lipoproteins may play an important role.

Objective: The objective of the study was to determine the contribution of the severity of steatohepatitis to atherogenic dyslipidemia in patients with NAFLD.

Design: This was a cross-sectional study.

Setting: The study was conducted at a university hospital.

Patients: Patients were recruited from outpatient clinics or from the general population (n = 188).

Interventions: Measurement of hepatic triglyceride content by magnetic resonance spectroscopy, histology (liver biopsy), metabolic profile by means of an oral glucose tolerance test, and lipoprotein analyses were performed.

Outcomes: Outcomes measured included standard lipids, lipoprotein subfraction analysis (apolipoprotein B/A1 levels, low-density lipoprotein (LDL) particle size/phenotype, and LDL/high-density lipoprotein subfractions), and insulin resistance.

Results: Patients with NAFLD had severe insulin resistance, especially at the level of the adipose tissue, when compared with patients without NAFLD. Despite small differences in triglycerides and high-density lipoprotein-cholesterol, patients with NAFLD had a significantly higher plasma apolipoprotein B to apolipoprotein A1 ratio (0.66 ± 0.02 vs 0.58 ± 0.02, P = .01) and smaller LDL particle size (216.2 ± 0.7 vs 219.4 ± 1.1 Å, P = .01). Of note, these differences between patients with/without NAFLD were independent of the presence of obesity. Severity of steatohepatitis did not significantly influence the lipoprotein profile. Worse atherogenic dyslipidemia was best predicted by the degree of liver fat accumulation and adipose tissue and systemic insulin resistance.

Conclusions: NAFLD was associated with a worse atherogenic lipoprotein profile, regardless of similar body mass index and other clinical parameters. We speculate that this lipoprotein profile is driven mostly by liver fat content and insulin resistance and appears not to be worsened by obesity or the severity of liver disease (nonalcoholic steatohepatitis).