Low-density lipoprotein particle size in hepatic steatosis and metabolic syndrome

Abstract

Background: Hepatic steatosis (HS), the most frequent liver disorder, was reported to be an independent predictor of cardiovascular disease. HS, if combined with the metabolic syndrome (MetS), might have a synergistic effect on low-density lipoprotein (LDL) particle size.

Methods: Carotid intima-media thickness (IMT) and plaque formation, and HS were diagnosed ultrasonographically, and the MetS was diagnosed using the ATP III criteria in 274 healthy workers (mean age +/- SD, 43.5 +/- 7.1 yrs). LDL particle size was measured with density gradient ultracentrifugation, and subfractions were classified as large, buoyant LDL I (27.2 to approximately 28.5 nm) and small, dense LDL III (24.2~25.5). All participants were grouped into three categories: control, subjects with HS alone and those with both HS and the MetS.

Results: The subjects with HS alone were 84 (30.7%), whereas those with HS and the MetS were 46 (16.8%). LDL peak particle sizes showed significant negative correlations with carotid mean IMTs. LDL peak particle size and LDL I (%) decreased significantly in the HS, showing the lowest values in the subjects with both HS and the MetS, and their association was independent, even adjusted for potential confounders. LDL III also showed independent associations across the groups.

Conclusion: HS alone was more prevalent than HS combined with the MetS in general population. For the patients with HS alone, LDL particle size and carotid atherosclerosis were found to fall in the middle of the control and those with both HS and the MetS.

Figure 1

LDL peak particle size and subfractions in hepatic steatosis (HS) according to its combination with/without the metabolic syndrome (MetS). A. Mean values (with 95% CIs) of LDL peak particle size (nm), B. Large, buoyant LDL subfraction I (%), and C. Small, dense LDL subfraction III (%): All three values showed significant linear associations with the three categories (P < 0.001). * P < 0.01, **P < 0.001; compared with the control (Bonferroni comparison). ^† P < 0.05, ^†† P < 0.01; compared with the HS alone.

Figure 2

Scatter plots of carotid intima-media thickness (IMT) and LDL peak particle size. A. A scatter plot of both CCA mean IMT and LDL peak particle size, r = -0.14, P = 0.021; B. A scatter plot of both ICA mean IMT and LDL peak particle size, r = -0.16, P = 0.010.