Small Low-density Lipoprotein Concentration Research Articles

Relationship between Apolipoprotein E Genotype and Lipoprotein Profile in Patients with Coronary Heart Disease.

(1) Background: Apolipoprotein E(ApoE) plays a critical role in lipid transport. The specific allele of APOE being expressed is associated with the development of coronary heart disease (CHD), however the specific mechanisms by which ApoE drives disease are unclear. In this study, we investigated the relationship between APOE allele, lipoprotein metabolome, and CHD severity to provide evidence for the efficacy of clinical cholesterol-lowering therapy; (2) Methods: Blood samples were collected from 360 patients with CHD that were actively being treated with statins. The lipoprotein profile, including particle numbers, particle size, and lipoprotein composition concentrates, was measured by nuclear magnetic resonance (NMR) spectroscopy. The severity of CHD was determined by quantifying coronary angiography results using the Gensini scoring system; (3) Results: We found there was no significant difference in low-density lipoprotein cholesterol (LDL-C) levels among ε2+ (ε2 allele carriers, consisting of ε2/ε2 and ε2/ε3 genotypes), ε3 (consisting of ε3/ε3 and ε2/ε4 genotypes), and ε4+ (ε4 allele carriers, consisting of ε3/ε4 and ε4/ε4 genotypes) participants receiving statin treatment. Compared with the ε3 group, patients with the ε2+ genotype showed lower concentrations of total low-density lipoprotein (LDL), small-LDL, and middle-LDL particles, as well as a larger LDL size, higher very low-density lipoprotein (VLDL) composition concentrates, and higher intermediate density lipoprotein (IDL) composition concentrates. The ε4+ group showed higher concentrations of total LDL, small LDL particles, and LDL compositions with smaller LDL size. The higher level of small LDL concentration was associated with a high Gensini score (B = 0.058, p = 0.024). Compared with the ε3 group, the risk of increased branch lesions in the ε2+ group was lower (OR = 0.416, p = 0.027); (4) Conclusions: The specific allele of APOE being expressed can affect the severity of CHD by altering components of the lipoprotein profile, such as the concentration of small LDL and LDL size.

Association of rheumatoid arthritis disease activity and antibodies to periodontal bacteria with serum lipoprotein profile in drug naive patients

Objective: We investigated lipid concentrations, particle sizes and antibodies binding to periodontal bacteria Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis and to malondialdehyde-acetaldehyde (MAA) modified low-density lipoprotein in immunoglobulin (Ig) class A, G and M among patients with newly diagnosed rheumatoid arthritis (RA) in a population-based cohort.Methods: Concentrations and sizes of lipoprotein particles analysed by proton nuclear magnetic resonance spectroscopy and antibody levels to MAA modified low-density lipoprotein were studied at baseline and after one-year of follow-up. Serum Ig A and G class antibodies to periodontal bacteria were determined at baseline.Results: Sixty-three patients were divided into tertiles according to disease activity by disease activity score with 28 joint count and erythrocyte sedimentation rate (ESR) (<3.9, 3.9–4.7, >4.7). Small low-density lipoprotein concentration was lowest in the tertile with the highest disease activity. In high-density lipoprotein, the concentrations of total, medium and small particles decreased with disease activity. The particle size in low-density lipoprotein associated with disease activity and the presence of antibodies to P. gingivalis. Ig G and M antibodies to MAA modified low-density lipoprotein correlated with disease activity. Inflammation associated changes faded by one year.Conclusions: Drug naive RA patients had proatherogenic changes in lipid profiles, but they were reversible, when inflammation diminished.Key messagesPatients with drug naive rheumatoid arthritis showed proatherogenic lipid profiles.Reversible changes in lipid profiles can be achieved as response to inflammation suppression.Active therapy aimed at remission is essential in all patients with rheumatoid arthritis.

Polycystic ovary syndrome and nonalcoholic fatty liver in obese adolescents: association with metabolic risk profile

To investigate the relationship between liver fat and in vivo insulin sensitivity, body composition, abdominal adiposity, and lipid metabolism in obese adolescent girls with polycystic ovary syndrome (PCOS). Cross-sectional case-control study. Research center. Thirty Tanner stage V obese girls with PCOS. None. Liver fat, abdominal adiposity, in vivo insulin-stimulated glucose disposal, whole-body lipolysis, fat oxidation, lipoprotein particle size and concentration, and liver enzymes (alanine aminotransferase and aspartate aminotransferase). Fatty liver index <1 is indicative of fatty liver. Fatty liver was present in 6.7% of the individuals (6.7%). Levels of alanine aminotransferase and aspartate aminotransferase were not different between those with fatty liver vs. without. Fatty liver index was associated with age (r = -0.53), body mass index (r = -0.41), total (r = -0.43) and subcutaneous (r = -0.41) abdominal adiposity, insulin-stimulated glucose disposal (r = 0.36), and small, medium small, and very small low-density lipoprotein concentrations (r ≥ -0.43). In a multiple regression analysis, age, total T, race, and insulin-stimulated glucose disposal explained 43% of the variance (R(2) = 0.43) in fatty liver index, with age (R(2) = 0.28) and total T (R(2) = 0.11) being independent contributors. Liver fat is associated with increasing age, even in the narrow adolescent age range, increasing abdominal adiposity, worsening insulin sensitivity, and dyslipoproteinemia in obese adolescent girls with PCOS. Targeting these abnormalities early in the course of PCOS may halt future nonalcoholic fatty liver disease in adulthood.

Abstract 1248.5: Lipoprotein Changes in HIV-Infected Antiretroviral-Naïve Individuals after Starting Class-Sparing Antiretroviral Therapy: ACTG Study A5152s

Patients with human immunodeficiency virus (HIV) receiving antiretroviral therapy (ART) are at increased risk of cardiovascular disease (CVD). In HIV-infected patients on ART, abnormalities of serum lipoproteins and insulin resistance have been associated with endothelial dysfunction. However, the effects of ART on dyslipidemia and CVD risk have been difficult to study because of the complexity of ART regimens and varying metabolic effects between and within ART classes. This study evaluated the effects of three ART regimens on lipids and lipoproteins, markers of insulin and glucose metabolism, and endothelial function. This was a substudy of A5142, a prospective, multicenter study of 82 treatment-naïve HIV-infected individuals randomly assigned to receive one of 3 class-sparing HIV treatment regimens: nucleoside reverse transcriptase inhibitors (NRTIs) + the non-nucleoside reverse transcriptase inhibitor efavirenz, NRTIs + the protease inhibitor lopinavir/ritonavir (LPV/r), or NRTI-sparing regimen of efavirenz + LPV/r. Lipoprotein particle concentrations were measured by nuclear magnetic resonance spectroscopy. Endothelial function was evaluated by brachial artery flow-mediated vasodilation (FMD) at baseline and after 24 weeks. All values are medians (interquartile range). Total and small low-density lipoprotein concentrations increased by 152 (−49, +407, p&lt;0.01) and 130 (−98, +417, p&lt;0.01) nmol/L, respectively, especially in the 0.04). Very low-density lipoproteins also increased (p+0.01), with larger increases in the arms that contained LPV/r (p KW 0.022). High-density lipoproteins increased by 6.0 mcmol/L (+2.8, +10.4, p&lt;0.01), similarly in each arm. FMD increased by 1.48% (−0.20, +4.30%, p&lt;0.001) with similar changes in each arm. Changes in lipoproteins were not related to changes in markers of insulin/glucose metabolism or FMD. Effective ART is associated with increases in total and small low-density lipoproteins and very low-density lipoproteins, especially in regimens that contain LPV/r. Over 24 weeks, the vascular effects of ART-related lipid changes may be outweighed by beneficial effects on treatment of HIV infection.

Short-term changes in lipoprotein subclasses and C-reactive protein levels of hypertriglyceridemic adults on low-carbohydrate and low-fat diets

Diets designed to promote weight loss and improve atherogenic lipid profiles traditionally include a reduction in total fat and, in particular, saturated fats. This study was designed to test the efficacy of a low-fat diet vs a carbohydrate (CHO)-restricted (low-CHO) diet in hypertriglyceridemic patients on lipid profile, weight loss, high-sensitivity C-reactive protein (hs-CRP), and satiety. Twenty-eight hypertriglyceridemic subjects (based on fasting triacylglycerol [TG] levels exceeding 1.69 mmol/L) were randomized to either the low-CHO or low-fat diet for 8 weeks. Fasting bloods were acquired at weeks 0 and 8 and analyzed for lipids and hs-CRP. Body weight and other anthropometric measures were also obtained. Three random 24-hour food recalls were used to assess compliance during the trial and 2 recalls before randomization to permit individualized dietary education. A significant time-by-treatment interaction was observed (P = .045), wherein the small low-density lipoprotein cholesterol concentrations were reduced by 46% in the low-CHO-assigned subjects and increased by 36% for those assigned the low-fat plan. The observed decrease in TG (18%) among low-CHO subjects, in contrast to the 4% increase for low-fat group, was not significant, nor were there significant differences in hs-CRP, overall dietary compliance, satiety, or the magnitude of body weight loss between groups (low-CHO group, -3.8% vs low-fat group, -1.6%). Favorable reductions in small low-density lipoprotein concentrations after 8 weeks suggest that a moderately restricted carbohydrate diet (20% CHO as energy) can promote a less atherogenic lipid profile when compared to the low-fat diet.

Small low-density lipoprotein and small low-density lipoprotein/total low-density lipoprotein are closely associated with intima-media thickness of the carotid artery in Type 2 diabetic patients

Background The intima-media thickness (IMT) of the carotid artery, as determined by ultrasonography, is useful for reflecting the extent of subclinical atherosclerosis. We investigated the relationship between IMT and the serum concentrations of small low-density lipoprotein (LDL) in diabetic patients. Methods The study was conducted with 27 Type 2 diabetic patients (14 males and 13 females; mean age=62.6±8.3 years) and 12 age-matched healthy controls. The LDL subfraction was measured using a polyacrylamide gel electrophoresis method. Vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) concentrations were measured by an enzyme immunoassay. The IMT was expressed as the maximum IMT (Max-IMT) and average IMT (Ave-IMT) of the carotid artery, measured by ultrasonography. Results Both the IMT and the small LDL concentrations were significantly increased in the diabetic patients compared with the healthy participants. The IMTs were significantly correlated with small LDL concentration and small LDL/total LDL more than LDL concentrations by multivariate analysis. The IMTs were not significantly correlated with the serum VEGF or PDGF concentrations. The patients with a larger IMT had a significantly higher prevalence of hypertension or ischemic heart disease than did the patients with a normal IMT. Conclusions The increased small LDL concentrations and small LDL/total LDL, in addition to total LDL concentrations, in Type 2 diabetic patients are closely associated with increased IMT of the carotid artery.