Low-density lipoprotein cholesterol-to-apolipoprotein B ratio as a potential indicator of LDL particle size and plasma atherogenicity in type 2 diabetes.

AIMS: Atherogenic dyslipidemia, associated with small, dense low-density lipoprotein-cholesterol (S-LDL) particles and impaired metabolism of triglycerides (TGs) and high-density lipoprotein-cholesterol (HDL-c), leads to the development of atherosclerosis-related complications of type 2 diabetes mellitus. Based on the hypothesis that an LDL-c-to-apolipoprotein B ratio (LDL/ApoB) < 1.2 may predict the prevalence of S-LDL, this study aimed to evaluate the LDL/ApoB ratio in patients with type 2 diabetes with moderately elevated TG levels. METHODS: The study population consisted of 121 outpatients with type 2 diabetes (S-LDL group, LDL/ApoB < 1.2, n = 79; L-LDL group, LDL/ApoB > 1.2, n = 42) and 58 healthy subjects. The LDL/ApoB ratio was calculated from the measured LDL-c and ApoB levels in participants with TG levels lower than 4.5 mmol/L. Since TGs and HDL-c are included in the atherogenic index of plasma (AIP), we evaluated the relationship between LDL/ApoB and the AIP. RESULTS: Higher levels of AIP, TG (both P < 0.0001), and lipid hydroperoxides (LOOH) (P < 0.001) and lower levels of HDL-c, total cholesterol, and non-HDL-c (P < 0.001, <0.01, <0.05, respectively) were found in the S-LDL group compared to the L-LDL group. There were significant relationships between the LDL/ApoB ratio and the AIP, TG (both P < 0.0001), LOOH (P < 0.0005), and HDL-c levels (P < 0.05) in the S-LDL group. CONCLUSIONS: The prevalence of S-LDL particles (65%) and the close association of LDL/ApoB with the AIP suggest that this ratio may be a potential indicator of increased cardiovascular risk in patients with type 2 diabetes.

Clinical Utility of the Logarithmically Transformed Ratio of Triglycerides-to- High-Density Lipoprotein Cholesterol and Its Relationship with Other Atherosclerosis-Related Lipid Factors in Type 2 Diabetes.

Background: Elevated triglyceride (TG) levels and reduced high-density lipoprotein-cholesterol (HDL-c) levels indicate lipid abnormalities, but their levels alone do not reflect the actual status of plasma atherogenicity and cardiovascular disease risk (CVD). TG and HDL-c levels directly affect the balance between plasma atherogenic and antiatherogenic factors, as well as values of the atherogenic index of plasma [AIP (logarithmically transformed ratio of TG-to-HDL-c)]. The aim of this study was to evaluate the AIP risk categories (an indicator of plasma atherogenicity) and the relationships of AIP with other atherosclerosis-related lipid parameters in patients with type 2 diabetes mellitus (T2DM) and their potential clinical utility. Methods: Standard lipid profile, AIP, and lipid hydroperoxides (LOOH) were investigated in 124 T2DM outpatients (mean age 52.7 ± 5.9 years) and 61 healthy subjects (mean age 50.9 ± 6.8 years). T2DM patients were subclassified according to the AIP risk category and glycemic control. Results: Higher levels of AIP, LOOH, and TG and lower HDL-c (all P < 0.0001) were observed in T2DM patients than in the control group. AIP positively correlated with LOOH, non-HDL-c, and the non-HDL/HDL ratio (all P < 0.0001). The TG level was strongly correlated with the LOOH level among T2DM patients (P < 0.0001). Conclusions: The close association of AIP with other atherosclerosis-related lipid factors reveals an increased plasma atherogenicity. AIP risk categories indicate the actual status of plasma atherogenicity and identify subjects who are at an increased atherogenic risk and the development of CVD. In this respect, AIP has a promising future in routine clinical practice.