Plasma fatty acids and lipoproteins in type 2 diabetic patients

The dyslipidemia of type 2 diabetic patients is characterized by high VLDL, abnormal LDL composition and low HDL cholesterol concentrations. The aim of this study was to establish whether the type of dietary fats affects LDL size and density and HDL cholesterol concentrations in these patients.

Plasma phospholipid fatty acid composition, which reflects the type of dietary fatty acids, was quantified by gas chromatography. LDL relative flotation (LDL-Rf), a measure of LDL particle size and density, was determined by single vertical spin density gradient ultracentrifugation in 97 type 2 diabetic patients.

By linear regression analysis of the data, plasma fatty acids were associated neither with LDL-cholesterol levels nor with LDL-Rf. The HDL cholesterol concentrations were negatively related with saturated fatty acids (r = -0.23; p = 0.02) but positively related with monounsaturated fatty acids (r = +0.20; p = 0.00). Furthermore, higher HDL concentrations were associated with large and buoyant LDL particles (HDL cholesterol vs LDL-Rf: r = +0.47; p = 0.00). In the multiple regression analysis, the LDL-Rf was significantly related both to triglycerides (beta coefficient = -0.55, p = 0.000) and HDL cholesterol (beta coefficient = 0.19, p = 0.034) concentrations. In a stepwise regression analysis including both triglycerides and HDL cholesterol, triglycerides alone explained the 43.0% of the LDL-Rf variability.

A reduction of the dietary saturated fats and an increment of monounsaturated fats might increase HDL cholesterol concentrations in type 2 diabetic patients. Modifications of LDL composition might be expected from interventions aimed to reduce plasma triglycerides.