Association of HDL Subfraction Profile with the Progression of Insulin Resistance.

Type 2 diabetes mellitus (T2DM) is a major global public health problem, as it is associated with increased morbidity, mortality, and healthcare costs. Insulin resistance (IR) is a condition characterized by disturbances in carbohydrate and lipid metabolism that precedes T2DM. The aim of the present study was to investigate the association between HDL and its subfraction profile and the progression of IR, as assessed by the Homeostatic Model Assessment for IR (HOMA-IR) index, and to define cut-off values to identify an increased risk of IR. Individuals with a HOMA-IR greater than 3.63 were considered to have IR. The HDL subfractions were separated using the Lipoprint system, which identifies ten subfractions (HDL-1-10) in three subclasses as large (HDL-L), intermediate (HDL-I) and small (HDL-S). Analyses were performed on samples from 240 individuals without IR and 137 with IR from the Hungarian general and Roma populations. The HDL-1 to -6 subfractions and the HDL-L and -I classes showed a significant negative association with the progression and existence of IR. Among them, HDL-2 (B = -40.37, p = 2.08 × 10-11) and HDL-L (B = -14.85, p = 9.52 × 10-10) showed the strongest correlation. The optimal threshold was found to be 0.264 mmol/L for HDL-L and 0.102 mmol/L and above for HDL-2. Individuals with HDL-L levels below the reference value had a 5.1-fold higher risk of IR (p = 2.2 × 10-7), while those with HDL-2 levels had a 4.2-fold higher risk (p = 3.0 × 10-6). This study demonstrates that the HDL subfraction profile (especially the decrease in HDL-2 and -L) may be a useful marker for the early detection and intervention of atherogenic dyslipidemia in subjects with impaired glucose and insulin metabolism.

Association of CETP Gene Polymorphisms and Haplotypes with Cardiovascular Risk.

Cholesteryl ester transfer protein (CETP) is known to influence HDL-C levels, potentially altering the profile of HDL subfractions and consequently cardiovascular risk (CVR). This study aimed to investigate the effect of five single-nucleotide polymorphisms (SNPs; rs1532624, rs5882, rs708272, rs7499892, and rs9989419) and their haplotypes (H) in the CETP gene on 10-year CVR estimated by the Systematic Coronary Risk Evaluation (SCORE), the Framingham Risk Score for Coronary Heart Disease (FRSCHD) and Cardiovascular Disease (FRSCVD) algorithms. Adjusted linear and logistic regression analyses were used to investigate the association of SNPs and 10 haplotypes (H1-H10) on 368 samples from the Hungarian general and Roma populations. The T allele of rs7499892 showed a significant association with increased CVR estimated by FRS. H5, H7, and H8 showed a significant association with increased CVR based on at least one of the algorithms. The impact of H5 was due to its effect on TG and HDL-C levels, while H7 showed a significant association with FRSCHD and H8 with FRSCVD mediated by a mechanism affecting neither TG nor HDL-C levels. Our results suggest that polymorphisms in the CETP gene may have a significant effect on CVR and that this is not mediated exclusively by their effect on TG and HDL-C levels but also by presently unknown mechanisms.

Distinct Fatty Acid Compositions of HDL Phospholipids Are Characteristic of Metabolic Syndrome and Premature Coronary Heart Disease-Family Study.

HDL particles can be structurally modified in atherosclerotic disorders associated with low HDL cholesterol level (HDL-C). We studied whether the lipidome of the main phosphatidylcholine (PC), lysophosphatidylcholine (LPC) and sphingomyelin (SM) species of HDL2 and HDL3 subfractions is associated with premature coronary heart disease (CHD) or metabolic syndrome (MetS) in families where common low HDL-C predisposes to premature CHD. The lipidome was analyzed by LC-MS. Lysophosphatidylcholines were depleted of linoleic acid relative to more saturated and shorter-chained acids containing species in MetS compared with non-affected subjects: the ratio of palmitic to linoleic acid was elevated by more than 30%. A minor PC (16:0/16:1) was elevated (28-40%) in MetS. The contents of oleic acid containing PCs were elevated relative to linoleic acid containing PCs in MetS; the ratio of PC (16:0/18:1) to PC (16:0/18:2) was elevated by 11-16%. Certain PC and SM ratios, e.g., PC (18:0/20:3) to PC (16:0/18:2) and a minor SM 36:2 to an abundant SM 34:1, were higher (11-36%) in MetS and CHD. The fatty acid composition of certain LPCs and PCs displayed a characteristic pattern in MetS, enriched with palmitic, palmitoleic or oleic acids relative to linoleic acid. Certain PC and SM ratios related consistently to CHD and MetS.

Low plasma apolipoprotein E-rich high-density lipoprotein levels in patients with metabolic syndrome.

BACKGROUND: High-density lipoprotein (HDL) containing apolipoprotein E (apoE-rich HDL) represents a small portion of plasma HDL. We recently established a method for measuring plasma apoE-rich HDL. This study aimed to investigate the relationship between metabolic syndrome (MetS) and apoE-rich HDL levels. METHODS: The apoE-rich HDL-cholesterol (HDL-C) levels and metabolic characteristics of 113 patients were analyzed. RESULTS: The MetS group (n = 58) had significantly lower apoE-rich HDL-C and a lower apoE-rich HDL-C/HDL-C ratio (apoE-HDL (%)) compared to the non-MetS group. The prevalence of MetS was increased when apoE-HDL (%) decreased. In simple regression analyses, apoE-HDL (%) was significantly inversely correlated with visceral fat area (rs = -0.370, P < 0.001) and plasma triglycerides (rs = -0.447, P < 0.001) and positively correlated with low-density lipoprotein (LDL) mean particle size (rs = 0.599, P < 0.001) and HDL mean particle size (rs = 0.512, P < 0.001). Stepwise multiple regression analysis revealed that LDL mean particle size, a component of the atherogenic lipoprotein profile, was an independent predictor of apoE-HDL (%) (adjusted R2 = 0.409). CONCLUSIONS: Plasma apoE-rich HDL levels might be a valuable indicator of MetS. These findings may help further understand HDL subfraction analysis in cardiometabolic diseases.

Diabetes-induced Alterations in HDL Subfractions Distribution.

INTRODUCTION: Diabetes mellitus (DM) due to its increasing prevalence and associated morbidity and mortality has become a serious public health problem. In DM, HDL may lose its beneficial features and become proatherogenic due to its altered biological activity thus increasing cardiovascular risk. The aim of this study was to assess the influence of the presence of diabetes mellitus type 2 and its duration on the distribution of HDL subfractions. Moreover, the effect of statin treatment on HDL subfraction share was analysed in this study. METHODS: The study group consisted of 50 patients with newly diagnosed DM and 50 persons with DM for longer than 10 years while the control group consisted of 50 healthy volunteers. HDL subfractions were analysed with the use of Lipoprint. RESULTS: We demonstrated progressive worsening of heart functioning and impairment of its structure in the course of diabetes mellitus. Moreover, we observed that HDL-6 subfraction and intermediate HDL fraction are lowest in the group with advanced DMt2 compared to the group with newly diagnosed DM and a healthy control group. Finally, the results of our study indicated the effect of statin treatment on HDL subfractions that seems not to be advantageous. CONCLUSION: It seems that in patients with diabetes mellitus compromised antiatherogenic properties of HDL, as a result of oxidative modification and glycation of the HDL protein as well as the transformation of the HDL proteome into a proinflammatory protein, increase cardiovascular risk.

High-Density Lipoprotein Subclasses and Mild Cognitive Impairment: Study of Outcome and aPolipoproteins in Dementia (STOP-Dementia)1.

BACKGROUND: High-density lipoprotein (HDL) containing apolipoprotein A-I is associated with the pathogenesis of Alzheimer's disease (AD). HDL particle size is modified in the presence of pathological conditions, while the significance of the HDL particle size remains controversial. OBJECTIVE: The aim of this study was to investigate the HDL lipoprotein subclasses in mild cognitive impairment (MCI) and AD. METHODS: This cross-sectional study included 20 AD patients, 17 MCI patients, and 17 age-matched controls without cognitive impairment, selected from the database of the Study of Outcome and aPolipoproteins in Dementia (STOP-Dementia) registry. The diagnoses of AD and MCI were performed by expert neurologists according to the Diagnostic and Statistical Manual of Mental Disorders-Fifth Edition criteria. Serum HDL subclasses were measured by electrophoretic separation of lipoproteins using the Lipoprint System. The neutrophil-lymphocyte ratio (NLR), a marker of inflammation, was calculated by dividing the neutrophil count by the lymphocyte count. RESULTS: Small-sized HDL particle levels in the MCI group were significantly higher than in the control group, although there was no difference in serum HDL-cholesterol levels between MCI and control groups. NLR in the MCI group was higher than in the control group, but this difference was non-significant (p = 0.09). There was no difference in HDL subclasses or NLR between the AD and control groups. CONCLUSION: These findings suggest that HDL subclasses might be associated with the development of MCI.

Elevated resting heart rate is associated with the severity of coronary artery disease in non-treated patients who underwent coronary angiography: potential role of lipoprotein subfractions.

OBJECTIVE: To assess the association between resting heart rate (RHR) and lipoprotein subfractions to provide potential evidence for the relationship between RHR and severity of CAD. METHODS: A total of 1119 consecutive non-treated subjects scheduled for coronary angiography were enrolled. High-density lipoprotein (HDL) and low-density lipoprotein (LDL) separation were performed by Lipoprint System. The link of RHR with lipoprotein subfractions was assessed. RESULTS: Increased RHR was significantly associated with higher triglyceride, total cholesterol, non-HDL-cholesterol, and apolipoprotein B (all p < .01). Furthermore, data indicated that higher RHR was related to more severe CAD (all p < .05). In the following linear regression models, we observed that higher RHR (HRh bpm) was significantly associated with lower large HDL (ß = -0.073, p = .024) and higher small LDL subfraction (ß = 0.103, p = .005) after adjusting for potential confounders. CONCLUSIONS: Increased RHR was associated with more severe CAD, which may be partly due to the significant relation to atherogenic lipoprotein subfractions.

A rapid and precise method for measuring plasma apoE-rich HDL using polyethylene glycol and cation-exchange chromatography: a pilot study on the clinical significance of apoE-rich HDL measurements.

BACKGROUND: High-density lipoprotein (HDL) containing apolipoprotein E (apoE-rich HDL) represents only a small portion of plasma HDL. Reliable methods for determining and isolating apoE-rich HDL have not been well studied. METHODS: We established a novel analytical method for apoE-rich HDL using polyethylene glycol and a cation-exchange column (PEG-column method). Furthermore, we examined biochemical correlates of apoE-rich HDL-cholesterol (HDL-C) in 36 patients who underwent coronary computed tomographic angiography. RESULTS: Our PEG-column method demonstrated high reproducibility (coefficient of variation <3.52%) and linearity up to 15mg/dl for apoE-rich HDL-C concentrations. Isolated apoE-rich HDL exhibited a larger diameter (14.8nm) than apoE-poor HDL (10.8nm) and contained both apoE and apoA-I. ApoE-rich HDL-C concentrations correlated significantly with triglycerides (rs=-0.646), LDL size (rs=0.472), adiponectin (rs=0.476), and other lipoprotein components. No significant correlation was obtained with the coronary calcium score. Multiple regression analysis revealed that plasma triglycerides and adiponectin concentrations remained significant independent predictors of apoE-rich (adjusted R2=0.486) but not apoE-poor HDL-C. CONCLUSIONS: The PEG-column method demonstrated, to various degrees, significant correlations between HDL subfractions and several lipid-related biomarkers involved in an atherogenic lipoprotein profile. Our separation technique for apoE-rich HDL is useful to clarify the role of apoE-rich HDL in atherosclerosis.