Influence of Fatty Liver on Plasma Small, Dense LDL-Cholesterol in Subjects with and without Metabolic Syndrome

Aim: Small, dense low density lipoprotein (sLDL) is known as an atherogenic lipoprotein and is often associated with metabolic syndrome (MS). A high frequency of sLDL is found in hypertriglyceridemic subjects. Also, fatty liver (FL) is often associated with MS; therefore, we studied whether the association of FL increases sLDL-cholesterol (C) in subjects with MS. Methods: In total, 207 patients were enrolled in this study and FL was estimated by echogram. The presence of MS was diagnosed according to the Japanese Guidelines for the Definition of Metabolic Syndrome. Results: sLDL-C and sLDL-C/LDL-C in the MS group were higher than in the non-MS group. Also, sLDL-C and sLDL-C/LDL-C in the FL group were higher than in the non-FL group. The simple correlation coefficient (r) between plasma triglyceride and sLDL-C or sLDL-C/LDL-C in all subjects was 0.36 and 0.51. In the MS group, r values were 0.32 and 0.52 while, in the non-FL group, r was 0.32 and 0.38, respectively. Two-way ANOVA revealed that FL was a powerful determinant of plasma sLDL-C and sLDL-C/LDL-C, but MS was not. When we divided all subjects into four groups, i.e., MS(-) FL(-), MS(-) FL(+), MS(+) FL(-) and MS(+) FL(+), sLDL-C/LDL-C of MS(+) FL(+) was significantly higher than all other groups. Conclusion: Association of MS and FL significantly increased sLDL-C and sLDL-C/LDL-C. The significant relationship between sLDL-C/LDL-C and plasma triglyceride in the FL group indicates that FL may produce triglyceride-rich VLDL, a precurser of sLDL, thereby contributing to the appearance of sLDL particles in the plasma of MS patients with FL.