Mean LDL Size Research Articles

Decreased Serum Stromal Cell-Derived Factor-1 in Patients with Familial Hypercholesterolemia and Its Strong Correlation with Lipoprotein Subfractions.

Stromal cell-derived factor-1 (SDF-1) is a chemokine that exerts multifaceted roles in atherosclerosis. However, its association with hyperlipidemia is contradictory. To date, serum SDF-1 and its correlations with lipid fractions and subfractions in heterozygous familial hypercholesterolemia (HeFH) have not been investigated. Eighty-one untreated patients with HeFH and 32 healthy control subjects were enrolled in the study. Serum SDF-1, oxidized LDL (oxLDL) and myeloperoxidase (MPO) were determined by ELISA. Lipoprotein subfractions were detected by Lipoprint. We diagnosed FH using the Dutch Lipid Clinic Network criteria. Significantly lower serum SDF-1 was found in HeFH patients compared to healthy controls. Significant negative correlations were detected between serum total cholesterol, triglycerides, LDL-cholesterol (LDL-C), apolipoprotein B100 (ApoB100) and SDF-1. Furthermore, serum SDF-1 negatively correlated with VLDL and IDL, as well as large LDL and large and intermediate HDL subfractions, while there was a positive correlation between mean LDL-size, small HDL and SDF-1. SDF-1 negatively correlated with oxLDL and MPO. A backward stepwise multiple regression analysis showed that the best predictors of serum SDF-1 were VLDL and oxLDL. The strong correlation of SDF-1 with lipid fractions and subfractions highlights the potential common pathways of SDF-1 and lipoprotein metabolism, which supports the role of SDF-1 in atherogenesis.

Relationship between serum Betatrophin, GPIHBP1, and LDL subfractions in patients with gestational diabetes mellitus

ObjectivesGestational diabetes mellitus (GDM) leads to changes in the lipid metabolism. In this study, we aimed to compare serum levels of LDL subfractions, betatrophin, and glycosylphosphatidylinositol-anchored high-density lipoprotein binding protein 1 (GPIHBP1) between patients with GDM and healthy pregnant women. Design and MethodsWe designed a prospective case-control study with 41 pregnant women. Subjects were divided into two groups: GDM and control. Betatrophin and GPIHBP1 levels were measured by ELISA method. Lipoprint LDL subfraction kit was used to perform LDL subfraction analysis electrophoretically. ResultsSerum levels of LDL6 subfraction, betatrophin, and GPIHBP1 were found to be higher in GDM group compared to the controls (p < 0.001). The mean LDL size were also found larger in GDM group. A positive correlation was found between betatrophin and GPIHBP1 levels (rho = 0.96, p < 0.001). ConclusionsOur findings suggest that betatrophin, and GPIHBP1 levels were found to be increased in GDM. This maybe the result of adaptive mechanisms in response to insulin resistance, but also this relationship should be evaluated for their effects on impaired lipid metabolism and lipoprotein lipase metabolism. There is a need for further prospective studies with larger samples to fully elucidate the mechanisms of this relationship both in pregnant patients and the other patient groups.

Association between Nordic and Mediterranean diets with lipoprotein phenotype assessed by 1HNMR in children with familial hypercholesterolemia

Background and aimsBoth Nordic and Mediterranean diets are considered healthy despite notable regional differences. Although these dietary patterns may lower cardiovascular risk, it is unclear if they improve the lipoprotein phenotype in children with familial hypercholesterolemia (FH). The aim is to determine the impact of Nordic and Mediterranean diets on the advanced lipoprotein profile in children with heterozygous FH (HeFH). MethodsThis was a cross-sectional study performed in children with FH recruited from the Lipid Clinics at Sant Joan University Hospital in Reus (Spain) and Oslo University Hospital (Norway).Two-hundred fifty-six children (mean age 10 y/o; 48% girls): 85 Spanish and 29 Norwegian FH children, and 142 non-FH healthy controls (119 from Spain and 23 from Norway) were included in the study. A pathogenic FH-associated genetic variant was present in 81% of Spanish children with FH and all Norwegian children with FH. An 1H NMR based advanced lipoprotein test (Nightingale®) providing information on the particle number, size and lipid composition of 14 lipoprotein subclasses was performed and correlated to the dietary components. ResultsLevels of LDL-C, HDL-C and triglycerides were not significantly different between the Nordic and Mediterranean FH groups. Spanish children with FH had more LDL particles, mainly of the large and medium LDL subclasses, than Norwegian FH children. Spanish FH children also had more HDL particles, mainly medium and small, than Norwegian FH children. The mean LDL size of Spanish FH children was larger, while the HDL size was smaller than that of the Norwegian FH children. The HDL particle number and size were the main determinants of differences between the two groups. In Norwegian children with FH, dietary total fat and MUFAs showed a significant correlation with all apolipoprotein B-containing lipoproteins and LDL size, whereas there was no correlation to SFA. A weaker association pattern was observed in the Spanish children. ConclusionsThe lipoprotein profiles of Spanish and Norwegian children showed differences when studied by 1H NMR. These differences were in part associated with differences in dietary patterns.

Impaired Organokine Regulation in Non-Diabetic Obese Subjects: Halfway to the Cardiometabolic Danger Zone

Altered organokine expression contributes to increased cardiometabolic risk in obesity. Our aim was to evaluate the associations of serum afamin with glucose homeostasis, atherogenic dyslipidemia, and other adipokines in severe obesity to clarify the early metabolic alterations. 106 non-diabetic obese (NDO) subjects and 62 obese patients with type 2 diabetes matched for age, gender, and body mass index (BMI) were enrolled in this study. We compared their data with 49 healthy, lean controls. Serum afamin and retinol-binding protein 4 (RBP4), as well as plasma plasminogen activator inhibitor-1 (PAI-1), were measured with ELISA, and lipoprotein subfractions were analyzed using Lipoprint gel electrophoresis. Afamin and PAI-1 found to be significantly higher in the NDO and T2M group (p < 0.001 and p < 0.001, respectively) than in the controls. In contrast, RBP4 was unexpectedly lower in the NDO and T2DM group compared to controls (p < 0.001). Afamin showed negative correlations with mean LDL size and RBP4, but positive correlations with anthropometric, glucose/lipid parameters, and PAI-1 in both the overall patients and the in NDO + T2DM groups. BMI, glucose, intermediate HDL, and small HDL were predictors of afamin. Afamin may serve as a biomarker for the severity of cardiometabolic disturbances in obesity. The complexity of organokine patterns in NDO subjects draws attention to the diverse spectrum of obesity-related comorbidities.

Afamin Levels and Their Correlation with Oxidative and Lipid Parameters in Non-diabetic, Obese Patients

Background: Afamin is a liver-produced bioactive protein and features α- and γ-tocopherol binding sites. Afamin levels are elevated in metabolic syndrome and obesity and correlate well with components of metabolic syndrome. Afamin concentrations, correlations between afamin and vitamin E, afamin and lipoprotein subfractions in non-diabetic, obese patients have not been fully examined. Methods: Fifty non-diabetic, morbidly obese patients and thirty-two healthy, normal-weight individuals were involved in our study. The afamin concentrations were measured by ELISA. Lipoprotein subfractions were determined with gel electrophoresis. Gas chromatography–mass spectrometry was used to measure α- and γ tocopherol levels. Results: Afamin concentrations were significantly higher in the obese patients compared to the healthy control (70.4 ± 12.8 vs. 47.6 ± 8.5 μg/mL, p < 0.001). Positive correlations were found between afamin and fasting glucose, HbA1c, hsCRP, triglyceride, and oxidized LDL level, as well as the amount and ratio of small HDL subfractions. Negative correlations were observed between afamin and mean LDL size, as well as the amount and ratio of large HDL subfractions. After multiple regression analysis, HbA1c levels and small HDL turned out to be independent predictors of afamin. Conclusions: Afamin may be involved in the development of obesity-related oxidative stress via the development of insulin resistance and not by affecting α- and γ-tocopherol levels.

No effect of vitamin D administration plus dietary intervention on emerging cardiovascular risk factors in patients with metabolic syndrome

BackgroundPatients with metabolic syndrome (MetS) have low serum 25-hydroxyvitamin D (25(OH)VitD) levels. Low 25(OH)VitD has been associated with several emerging cardiovascular disease (CVD) risk factors, while VitD administration may ameliorate them. AimTo study the effect of 25(OH)VitD supplementation plus dietary instructions on novel CVD risk factors in MetS patients. MethodsThis is a pre-specified analysis of a previously published study. Patients with MetS (n = 50, 52 ± 10 years) were given dietary instructions and were randomized to receive either 25(OH)VitD, 2.000 IU/day p.o. (Suppl group) or nothing (No-Suppl group). Serum 25(OH)VitD, small dense low-density lipoprotein cholesterol (sdLDL), as well as lipoprotein-associated phospholipase A2 (LpPLA2) activity, leptin and adiponectin levels were measured at baseline and 3 months later. ResultsIn the Suppl group 25(OH)VitD levels increased by 90% [from 16.1 (3.3–35.1) to 30.6 (8.4–67.6) ng/mL, p = 0.001] and by 33.3% [from 9.9 (4.0–39.6) to 13.2 (3.5–36.8) ng/mL, p = NS] in the No-Suppl group. sdLDL serum levels, mean LDL size, LpPLA2 activity, leptin, adiponectin concentration and leptin to adiponectin ratio did not change significantly in both groups. ConclusionIn this small study the administration of 25(OH)VitD plus dietary intervention in patients with MetS were not associated with any significant change in various emerging CVD risk factors. (NCT01237769 ClinicalTrials.gov).

Plasminogen Activator Inhibitor-1 Level Correlates with Lipoprotein Subfractions in Obese Nondiabetic Subjects.

Background The elevated level of plasminogen activator inhibitor-1 (PAI-1) in obese subjects with metabolic syndrome and in patients with type 2 diabetes is well established. The association of plasma PAI-1 and lipid metabolism is still unclear. The aim of the present study was to determine the relationship between plasma PAI-1 levels and the distribution of lipoprotein subfractions in obese and lean nondiabetic individuals. Subjects and Methods We enrolled fifty nondiabetic obese patients and thirty-two healthy volunteers. Lipoprotein subfractions were detected with Lipoprint System. Plasma PAI-1, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and myeloperoxidase (MPO) concentrations were determined with enzyme-linked immunosorbent assay (ELISA), while serum paraoxonase-1 (PON1) activities were measured by spectrophotometry. Results The TNF-α, IL-6, oxidized low-density lipoprotein (oxLDL), and MPO levels were found to be significantly higher, while PON1 paraoxonase and arylesterase activities were nonsignificantly lower in the obese patients. Strong significant negative correlations were found between plasma PAI-1 concentration and mean LDL size, as well as between PAI-1 concentrations and the levels of the large and intermediate high-density lipoprotein (HDL) subfractions. In multiple regression analysis, PAI-1 was predicted by waist circumference and intermediate HDL subfraction. Conclusion The significant correlations between PAI-1 levels and lipoprotein subfractions indicate the link between PAI-1 and lipid metabolism in obesity.

Effect of Moderate Intensity Exercise Dose on Lipoprotein Concentrations and Particle Size in Older Women

Lipoprotein concentrations are well established biological markers associated with cardiovascular disease (CVD) risk. Recent research has placed great importance on the function of different lipoprotein subfractions (medium and small VLDL; small and large LDL; small, medium and large HDL). Current literature supports exercise as being protective by affecting lipoprotein particle size and concentration, whereas little research has been conducted to determine the effects of exercise dose on these outcomes. PURPOSE: To determine if exercise dose has an effect on VLDL, LDL, and HDL particle size and concentrations in older sedentary women after 16 weeks of moderate-intensity aerobic exercise. METHODS: Sixty-five women (age = 64.7 + 4.2 years) were randomized into higher-dose (n = 30) and lower-dose (n = 35) exercise groups. Supervised treadmill walking sessions lasted approximately 35 or 55 minutes, 3 times per week, for lower-dose and higher-dose groups, respectively. All exercise was completed at an intensity of 50-55% of heart rate reserve. Fasting plasma samples were collected before and after exercise intervention. Plasma lipoprotein particle concentrations and average sizes were determined by nuclear magnetic resonance spectroscopy. RESULTS: Exercise, in the entire sample, lowered total HDL and small VLDL particle concentration (1.5 ± 3.6 μmol/L and 4.2 ± 16.4 nmol/L; p<0.01 and p<0.05, respectively), and increased mean HDL particle size (0.1 ± 0.3 nm; p<0.01). When analyzed by exercise groups, the lower-dose group displayed a decrease in total HDL particle concentration (1.9 ± 3.1 μmol/L; p=0.001), while the higher-dose group displayed an increase in mean LDL particle size (0.3 ± 0.5 nm; p<0.05). Both exercise higher-dose and lower-dose treatments were found to significantly increase mean HDL particle size (0.1 ± 0.2 nm and 0.1 ± 0.3 nm, respectively; p<0.05) with no significant difference between groups. CONCLUSIONS: The results from this study support that exercise in sedentary older women decreased CVD risk. Though the HDL particle concentration decreased in the lower- dose group, maintenance of HDL particle concentration in the higher-dose group along with the increase in mean HDL and LDL size are characteristics associated with lower CVD risk. Supported by NIH Grant R00AG031297

Comparing the Impact of Saturated Fatty Acids from Different Dairy Sources on LDL Particle Size Phenotype

BackgroundLow‐density lipoproteins (LDL) constitute a heterogeneous class of lipoproteins among which small and dense LDL may be more atherogenic than large LDL particles, independent of cholesterol concentrations. The aim of this study was to examine how consumption of saturated fat (SFA) from different dairy sources modifies the LDL particle size phenotype compared with other dietary fats (monounsaturated ‐ MUFA and polyunsaturated fat‐ PUFA) and a low‐fat diet/high carbohydrate diet.MethodsA randomized crossover controlled trial was conducted in 92 men and women with abdominal obesity and relatively low HDL‐C. Subjects were assigned to sequences of 5 isoenergetic diets of 4 weeks each (Table): 1) a diet rich in SFA from cheese (CHEESE); a diet rich in SFA from butter (BUTTER); a diet rich in MUFA; a diet rich in PUFA and a low‐fat, high carbohydrate diet (CHO). All foods were provided to the participants during the experimental phases. Features of the LDL particle size phenotype (mean LDL particle size, proportion of small and large) were assessed by one dimension nondenaturing polyacrylamide gel electrophoresis.ResultsLDL particle size at baseline (mean±SD) in women was larger than in men (252.24±2.85 vs. 251.67±3.49, p=0.04), although differences were no longer significant after adjustment for waist circumference. The CHEESE diet had no significant impact on all phenotypic measures of LDL particle size compared with BUTTER, CHO, MUFA and PUFA. Consumption of the BUTTER diet significantly increased LDL mean size compared with CHO (p=0.021) and MUFA (p=0.005). The increase in mean LDL size with BUTTER was more apparent among individuals with small LDL particles at baseline than among those with large LDL (P treatment × baseline LDL size=0.047). There was no difference in the distribution of small and large LDL particles among diets.ConclusionsResults from this full‐feeding study suggest 1‐ that SFA from butter and cheese have similar effects on features of the LDL particle size phenotype, and 2‐ that consumption of SFA from butter may be associated with less atherogenic LDL particles. These data are partly consistent with the fact that consumption of cheese and butter are not associated with an increased risk of cardiovascular disease.Support or Funding InformationSource of Research Support : Dairy Research Cluster Initiative (Dairy Farmers of Canada, Agriculture and Agri‐Food Canada, the Canadian Dairy Network and the Canadian Dairy Commission). Macronutrient (% energy), calcium and sodium content of experimental diets CHEESE BUTTER MUFA PUFA CHO Lipids (%) 32.0 32.0 32.0 32.0 25.0 SFA (%) 12.6 12.4 5.8 5.8 5.8 MUFA (%) 12.5 12.3 19.6 12.6 12.6 PUFA (%) 4.8 4.8 4.8 11.5 4.8 Carbohydrates (%) 51.9 52.0 51.9 51.9 58.9 Proteins (%) 16.0 16.0 16.0 16.0 16.0 Calcium (mg/2500 kcal) 1261 811 812 812 842 Sodium (mg/2500 kcal) 2482 2480 2479 2479 2485 Fibers (g/2500kcal) 31 31 31 31 31

The New Molecular Entity Evolocumab, One Kind of PCSK9 Inhibitor, Reduce Plasma Small Size LDL-Cholesterol Levels by Using a New Standardized Method of Measuring LDL Size

Aims: There has been no evidence on the effects of evolocumab, protein convertase subtilisin/kexin type 9 (PCSK9) inhibitor, on small size LDL. We observationally investigated the efficacy and side effects of evolocumab on the LDL subfraction particle diameter using PAGE system for lipoprotein analysis. Methods: We defined 30 patients with high-risk hyperlipidemia. As for analysis of LDL subfraction profile, we used polyacrylamide gel electrophoresis three methods: 1) 3% nondenatured poly-acrylamide gel electrophoresis method (3%PAGE), 2) 2% - 16% nondenatured poly-acrylamide gradient gel electro-phoresis method (2% - 16% GGE) and 3) 2.7% - 5% GGE. Evolocumab 140 mg/day administered together with statin significantly improved serum total cholesterol (TC), triglyceride (TG), high-dense lipoprotein-cholesterol (HDL-C), and LDL-C after four-week treatment. Results: TC, TG, HDL-C and LDL-C levels were improved by, respectively, 33%, 20%, 10%, and 54%. The mean LDL size significantly increased from 25.6 ± 0.4 nm to 26.4 ± 0.8 nm. The small dense LDL-cholesterol (sdLDL-C), large buoyant LDL-cholesterol (lbLDL-C), and mid-band lipoprotein-cholesterol were reduced, respectively. Therefore, the preliminary study on this paper can be the first step into a new insight on the world of lipid metabolism. Conclusion: Short-term administration of evolocumab addedons to statin therapy, significantly reduced small size LDL levels.

Effects of Small Dense LDL in Diabetic Nephropathy in Females with Type 2 Diabetes Mellitus

Objective: This study investigated the association between small-dense low-density lipoprotein (sdLDL) and diabetic nephropathy (DN) in type 2 diabetic patients. Methods: A total of 172 type 2 diabetic patients (95 men and 77 women) who had not taken lipid-lowering agents were enrolled in this study. Measured LDL cholesterol fractionates into seven parts (LDL1 through 7) according to the size and the extent of charge. Using this system, we analyzed mean LDL particle size and the proportion of sdLDL (the percent of LDL3 through 7 over whole LDL). DN was defined as the albumin-to-creatinine ratio (ACR) ≥30 mg/g after excluding other causes of proteinuria. Results: The mean LDL cholesterol, LDL cholesterol size, proportion of sdLDL and ACR did not differ significantly between males and females. The presence of DN was negatively correlated with mean LDL size (r=-0.33, p value=0.02) and positively correlated with the proportion of sdLDL (r=0.34, p value=0.01) in females but not in males. After adjusting for other confounding factors related to DN, mean LDL size and proportion of sdLDL remained independent risk factors for DN in females [for mean LDL size, Odds ratio (OR)=0.86, 95% Confidence interval (CI)=0.77-0.96, p=0.01; for proportion of sdLDL, OR=1.07, 95% CI: 1.10-1.12, p=0.01], but not in males. Conclusion: sdLDL is closely related to DN in female type 2 diabetic patients. Further studies are necessary to clarify the association of sdLDL and DN with gender. (J Lipid Atheroscler 2016 June;5(1):11-19)

Association between small dense LDL and early atherosclerosis in a sample of menopausal women

The association between small dense LDL particles and early atherosclerosis has been evaluated in a sample of middle-aged women.We analysed the relation between sd-LDL and common carotid intima media thickness in 228 menopausal women. LDL separation was performed by Lipoprint System: 7 LDL subfractions were obtained, mean LDL size and LDL score (% of sd-LDL) were calculated.Multivariate analysis showed a significant association between IMT (≥1.30mm) and mean LDL size after controlling for age (OR 7.80; 95% CI 1.47–41.39; p=0.016 for mean LDL particle size). IMT remained significantly related to mean LDL particle size after controlling for age and Apo B.In a subsequent multivariate analysis, after controlling for age, IMT (≥1.30mm) was significantly related to LDL score (OR 12.15; 95% CI 1.29–114.36; p=0.029 for LDL score), or age and Apo B (OR 10.13; 95% CI 1.07–95.71; p=0.043 for LDL score).Our results suggest an association between sd-LDL and IMT, independently of age and Apo B. This data may indicate that sd-LDL are markers of early carotid atherosclerosis, and suggest that measurement of sd-LDL-C gives useful information in the risk assessment for atherosclerotic disease in menopausal women.

Abstract P291: Adipocytokines, Lipoproteins &amp; Obesity Among Black &amp; White Postmenopausal Women from the Women’s Health Initiative

Background: Despite the prevalence of severe obesity, particularly among women and African-American women, there is little data on CV risk factor differences across the BMI spectrum including extreme obesity. Methods: Participants were 1200 black and white postmenopausal women sampled from the Women’s Health Initiative Observational Study according to BMI categories and waist circumference tertiles: 300 black and 300 white women with BMI 40-65 kg/m 2 and 75 black and 75 white women in BMI categories 8.5-&lt;25, 25-&lt;30, 30-&lt;35 and 35-&lt;40 kg/m 2 . Using stored baseline serum, total and high molecular-weight (HMW) adiponectin, leptin, ghrelin and insulin were measured by immunoassay; plasma lipoproteins and subclasses were measured by NMR spectroscopy. Race-ethnicity differences were tested in linear regression models adjusted for age, diabetes, BMI, waist, hip, hormone therapy and lipid-lowering medication. Results: Compared with white women, black women had lower levels of total and HMW adiponectin and ghrelin, and higher levels of insulin and leptin. Despite similar levels of total LDL particles (LDL-P), black women had lower levels of small LDL-P and higher levels of large LDL-P and larger mean LDL size. Levels of large HDL particles (HDL-P) and small HDL-P were also similar for black and white women, but black women had lower levels of total and medium HDL-P and larger mean HDL particle size. Black women also had lower levels of total, large, medium and small VLDL particles (VLDL-P) which increased little across BMI category, such that mean levels of total or large VLDL-P among black women with BMI≥ 40 kg/m 2 were lower than white women of normal BMI (&lt;25 kg/m 2 ) (Figure). Among white, but not black women, total LDL-P was higher and total HDL-P was lower with higher BMI category (Figure). Conclusions: Among postmenopausal women of similar BMI and waist circumference, black women have lower levels of ghrelin and total and HMW adiponectin, but better lipoprotein levels that are less related to obesity compared with white women.

Effect of rosuvastatin monotherapy or in combination with fenofibrate or ω-3 fatty acids on lipoprotein subfraction profile in patients with mixed dyslipidaemia and metabolic syndrome

Raised triglycerides (TG), decreased high-density lipoprotein cholesterol (HDL-C) levels and a predominance of small dense low density lipoproteins (sdLDL) are characteristics of the metabolic syndrome (MetS). To compare the effect of high-dose rosuvastatin monotherapy with moderate dosing combined with fenofibrate or ω-3 fatty acids on the lipoprotein subfraction profile in patients with mixed dyslipidaemia and MetS. We previously randomised patients with low-density lipoprotein cholesterol (LDL-C) > 160 and TG > 200 mg/dl to rosuvastatin monotherapy 40 mg/day (R group, n = 30) or rosuvastatin 10 mg/day combined with fenofibrate 200 mg/day (RF group, n = 30) or ω-3 fatty acids 2 g/day (Rω group, n = 30). In the present study, only patients with MetS were included (24, 23 and 24 in the R, RF and Rω groups respectively). At baseline and after 12 weeks of treatment, the lipoprotein subfraction profile was determined by polyacrylamide 3% gel electrophoresis. The mean LDL size was significantly increased in all groups. This change was more prominent with RF than with other treatments in parallel with its greater hypotriglyceridemic capacity (p < 0.05 compared with R and Rω). A decrease in insulin resistance by RF was also noted. Only RF significantly raised HDL-C levels (by 7.7%, p < 0.05) by increasing the cholesterol of small HDL particles. The cholesterol of larger HDL subclasses was significantly increased by R and Rω. All regimens increased mean LDL size; RF was the most effective. A differential effect of treatments was noted on the HDL subfraction profile.

A single 1-h session of moderate-intensity aerobic exercise does not modify lipids and lipoproteins in normolipidemic obese women

The purpose of this study was to quantify the effects of a single session of aerobic exercise on lipids and lipoproteins in women who were sedentary and obese. Women (n = 12) who were premenopausal, sedentary, and obese (body mass index, 30-40kg·m(-2); waist circumference> 88cm) completed exercise and control trials in a randomly assigned order. Exercise consisted of a single session of treadmill walking at 70% maximum oxygen uptake until 500kcal were expended, and the control protocol consisted of 60min of seated rest. Fasting blood samples were collected immediately prior to, 24h, and 48h following the exercise and control sessions and analyzed for triglyceride, total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), HDL(2)-C, and HDL(3)-C concentrations, and mean LDL, HDL(2), and HDL(3) particle size and cholesterol distributions. A 2× 3 (trial× time) ANOVA with repeated measures revealed no significant (p> 0.05) changes in the lipid and lipoprotein variables 24 and 48h following exercise. In contrast to previously published data in lean men and women, a single session of treadmill exercise at 70% maximum oxygen uptake that expended 500kcal was insufficient to modify lipids and lipoproteins in women who were sedentary, normolipidemic, and obese.

Lack of Association between Small Dense Low-Density Lipoprotein Levels and Coronary Artery Disease in Chronic Hemodialysis Patients

Background/Aims: Small, dense low-density lipoprotein (sd-LDL) is a newly recognized risk factor for coronary artery disease (CAD) in the general population. This study was performed to evaluate the relationship between sd-LDL, and CAD and cardiovascular risk factors such as other lipid profiles and hemostatic factors, in patients with chronic hemodialysis (CHD). Methods: Thallium single-photon emission computed tomography (SPECT) was performed to evaluate for CAD in 126 CHD patients. Coronary angiography was performed in patients with positive thallium SPECT. CHD patients were classified into CAD and non-CAD group. LDL subfractions, other lipid profiles, and hemostatic factors were measured. Results: The proportion of sd-LDL, and mean LDL size did not differ between CHD patients and healthy controls. Twenty-eight CHD patients had CAD by thallium SPECT and coronary angiography. The proportion of sd-LDL and mean LDL size did not differ between CAD and non-CAD patients. Age, diabetes mellitus presentation and high-sensitivity C-reactive protein (hs-CRP) levels were significantly higher, and prealbumin and apolipoprotein A1 levels were significantly lower, in the CAD group (p < 0.05). The proportion of sd-LDL was positively correlated with triglyceride levels (p < 0.001), apolipoprotein B (p < 0.05) and fibrinogen (p < 0.05). Conclusion: This study showed that sd-LDL is not increased in CHD patients and is not associated with CAD in such patients.

Abstract: 137 KINETICS OF APOB-CONTAINING LIPOPROTEINS: AN UPDATE

The association between small dense LDL particles and early atherosclerosis has been evaluated in a sample of middle-aged women.We analysed the relation between sd-LDL and common carotid intima media thickness in 228 menopausal women. LDL separation was performed by Lipoprint System: 7 LDL subfractions were obtained, mean LDL size and LDL score (% of sd-LDL) were calculated.Multivariate analysis showed a significant association between IMT (≥ 1.30 mm) and mean LDL size after controlling for age (OR 7.80; 95% CI 1.47–41.39; p = 0.016 for mean LDL particle size). IMT remained significantly related to mean LDL particle size after controlling for age and Apo B.In a subsequent multivariate analysis, after controlling for age, IMT (≥ 1.30 mm) was significantly related to LDL score (OR 12.15; 95% CI 1.29–114.36; p = 0.029 for LDL score), or age and Apo B (OR 10.13; 95% CI 1.07–95.71; p = 0.043 for LDL score).Our results suggest an association between sd-LDL and IMT, independently of age and Apo B. This data may indicate that sd-LDL are markers of early carotid atherosclerosis, and suggest that measurement of sd-LDL-C gives useful information in the risk assessment for atherosclerotic disease in menopausal women.

Adiponectin and Lipoprotein Particle Size

OBJECTIVEAdiponectin has been postulated to affect lipid and insulin signal transduction pathways. We evaluated the relationships of plasma adiponectin with lipoprotein mean particle size and subclass concentrations, independent of obesity and insulin sensitivity.RESEARCH DESIGN AND METHODSA cross-sectional analysis of 884 young Israeli adults who participated in the population-based Jerusalem Lipid Research Clinic (LRC) study was conducted. Lipoprotein particle size was assessed using proton nuclear magnetic resonance.RESULTSIn multivariable linear regression models that included sex, BMI, waist circumference, homeostasis model assessment of insulin resistance, and leptin, adiponectin was associated with mean LDL size (standardized regression coefficient B = 0.20; P < 0.001), VLDL size (B = −0.12; P < 0.001), and HDL size (B = 0.06; P = 0.013). Adiponectin was inversely related to large VLDL (P < 0.001) but positively to small VLDL (P = 0.02), inversely related to small LDL (P < 0.006) but positively to large LDL (P < 0.001), and positively related to large HDL (P < 0.001) subclass concentrations.CONCLUSIONSAdiponectin is favorably associated with lipoprotein particle size and subclass distribution independent of adiposity and insulin sensitivity.

The Effects Of Exercise Training On Maintenance Of Abdominal Adiposity And Lipoproteins During Weight Regain

Purpose The primary purpose was to investigate the effect of exercise training on maintaining weight loss induced improvements in metabolic fitness, specifically abdominal adiposity and lipoproteins, during weight regain. Secondarily, we examined the relationships between abdominal adiposity and lipoproteins during weight loss and regain. Methods Nineteen overweight to class I obese (BMI = 25–34.9) individuals (6 males,13 females) age 18–43 y participated in this 10 wk, two phase study. In phase I, subjects underwent 6 wk of modest energy restriction (∼500 kcal/d) and exercise training to induce a 5% reduction in body weight. During phase II, subjects were randomized into either a weight maintenance or partial weight regain group. Both groups continued exercise training. The maintain group slightly increased energy intake (+∼100 kcal/d) to achieve weight maintenance, while the regain group significantly increased energy intake (+∼600 kcal/d) to induce regain of 50% of initial weight loss. Exercise training during both phases consisted of 45 min/d, 5d/wk of walking to mild treadmill jogging at 60%VO2max. Lipoproteins and abdominal fat were assessed at three testing sessions: pre-weight loss (baseline), post Phase I treatment (wk 6), and post Phase II treatment (wk 11). RESULTS Weight loss resulted insignificant reductions in BMI, body fat %, total, subcutaneous, and intra-abdominal fat, triglyceride incremental peak (Peak1 TG), triglyceride incremental area under the curve (TG-AUCI), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and LDL1-C. Exercise training maintained changes in body fat %, total, subcutaneous, and intra-abdominal fat, Peak1 TG, and TG-AUC1, but was not successful at maintaining TC, LDL-C, LDL1 -C, or mean LDL size during weight regain. Changes in abdominal adiposity and lipoproteins were not significantly correlated during weight loss or weight regain. CONCLUSION Weight loss, induced by the combination of diet and exercise, is effective at improving many of metabolic syndrome parameters, and exercise training was effective at maintaining some of these improvements during partial weight regain. Finally, changes in abdominal adiposity during weight loss and partial weight regain were not related to changes in lipoproteins. Supported by: The MU Research Council and the MU College of Human Environmental Sciences: Margaret Mangel Catalyst Fund.

Decrease in LDL size in HIV-positive adults before and after lopinavir/ritonavir-containing regimen: an index of atherogenicity?

Background: Hypertriglyceridemia (HTG) is frequently observed during highly active antiretroviral therapy (HAART) including protease inhibitor. Apolipoprotein (apo) CIII could be involved in this HTG by inhibition of triglyceride (TG) hydrolysis, which leads to the occurrence of small dense low density lipoprotein (sdLDL), a recognized cardiovascular risk factor. Objective: To characterize the influence of lopinavir/ritonavir-containing regimen on lipoprotein profile. Design and methods: 24 antiretroviral-experienced HIV infected adults (including 14 patients in therapeutic interruption of at least 2 months) and 14 HIV uninfected healthy controls were enrolled. Serum lipid parameters (total cholesterol (TC), HDL-C, LDL-C, TG, apoA1, apoB, apoCIII), lipoprotein composition and LDL size were determined before initiation of lopinavir/ritonavir-containing regimen, and at 1 and 3 months thereafter. Results: At baseline an atherogenic lipid profile was evidenced, characterized by a moderate HTG associated to a smaller mean LDL size (25.16 vs 25.93 nm, P<0.001), an enrichment in TG of LDL (11.4 vs 6.0%, P<0.01) and a high prevalence of sdLDL (75 vs 7%, P<0.01) when compared to controls. After 1 month of lopinavir/ritonavir-containing regimen, a significant reduction of LDL size (24.81 vs 25.16 nm, P<0.05) and a significant increase in cholesterol total (5.53 vs 4.49 mmol/l, P<0.001), in TG (4.20 vs 2.01 mmol/l, P<0.001), in apoA1 (1.28 vs 1.11 g/l, P<0.001), in apoB (1.08 vs 0.94 g/l, P<0.01), in apoCIII (0.16 vs 0.10 g/l, P<0.001), in TG percentage in LDL (14.4 vs 11.4, P<0.05) and in TG percentage in HDL (10.2 vs 8.3, P<0.05) were observed. Conclusions: Advanced stage of HIV infection is associated with an atherogenic lipid profile including a high prevalence of sdLDL. Lopinavir/ritonavir-containing regimen accentuates the reduction of LDL size. Since fibrates decrease TG and increase LDL size, they appear as a logical option to manage HAART-induced HTG.