The role of circulating lipoprotein lipase and adiponectin on the particle size of remnant lipoproteins in patients with diabetes mellitus and metabolic syndrome

• RLP particle size in T2DM and MetS is significantly larger than in controls.
• RLP particle size is inversely correlated with LPL and adiponectin.
• Fatty liver and high TG are positively correlated with a large RLP particle size.

BackgroundThe factors regulating particle size of remnant lipoproteins (RLPs) in type 2 diabetes (T2DM) and metabolic syndrome (MetS) cases have not been well elucidated.MethodsT2DM, MetS and healthy controls with and without a fatty liver were studied. Remnant lipoprotein (RLP)-cholesterol (RLP-C) and RLP-triglyceride (RLP-TG), small dense LDL-cholesterol (sdLDL-C), lipoprotein lipase (LPL), hepatic triglyceride lipase (HTGL) and adiponectin concentrations were measured in the fasting pre-heparin plasma. The RLP particle size was estimated by the RLP-TG/RLP-C ratio.ResultsThe serum TG, RLP-C, RLP-TG, RLP-TG/RLP-C ratio and sdLDL-C were significantly greater in T2DM and MetS than in controls. Fatty liver and high serum TG were significantly associated with an increased RLP-TG/RLP-C ratio which was used to estimate the particle size of RLP in controls, T2DM and MetS. LPL and adiponectin in the pre-heparin plasma were inversely correlated with RLP-TG/RLP-C ratio in normal, T2DM and MetS. LPL was also positively correlated with adiponectin in all three cases.ConclusionsRLP particle size in T2DM and MetS was significantly larger than in controls and was regulated by circulating LPL and adiponectin, but not HTGL. Fatty liver and high TG were significantly associated with the prevalence of the large RLP particle size.