Large HDL-P Research Articles

Association between lipoprotein particle concentration and size and progression of coronary plaque: the MACS Longitudinal Coronary CT angiography study

Abstract Background People living with HIV have greater risk of cardiovascular diseases (CVD) than people without HIV and tend to have different risk profiles, including higher serum triglycerides and lower LDL cholesterol levels. Nuclear magnetic resonance (NMR) provides a detailed phenotype of lipoproteins. Purpose To examine the associations between lipoprotein particle concentrations and size and progression of coronary artery plaque among people living with and without HIV, and whether these associations differ by HIV serostatus. Methods Men with no clinical CVD in the Multicenter AIDS Cohort Study (MACS) who underwent a coronary CT angiography at baseline (2010-13) and follow-up (2015-17) were included. NMR spectroscopy was completed on fasting serum samples at baseline. Logistic regression models for the change in total coronary plaque volume (in tertiles) were estimated with NMR-derived lipoproteins as predictors. Levels were log-transformed and standardized to make results comparable. Models were adjusted for demographics, statin use and HIV serostatus (model 1) with addition of CVD risk factors (model 2). Interactions by HIV serostatus were also tested. Results A total of 549 men (314 with HIV; 235 without HIV) were included. Mean age was 53 ±7 years; 58% were White, 30% Black, and 12% Hispanic. Coronary plaque was present in 70% and plaque volume progressed in 79% of the cohort. Among men with HIV, 81% had undetectable HIV RNA and 12% had a diagnosis of AIDS at baseline. Men with HIV had significantly higher levels of small LDL-P, and total, medium and large VLDL-P levels compared to men without HIV, and lower levels of total, small and large HDL-P (Table 1). Men with HIV had significantly greater progression of plaque volume (37 mm3) compared to men without HIV (31 mm3, p<0.05). Levels of total and small LDL-P concentrations were directly associated with plaque progression, whereas large HDL-P was inversely associated with plaque progression in the combined sample (Model 2). Associations between total and small LDL-P with plaque progression were stronger in men with HIV than in men without HIV in models 1 and 2 (interaction p<0.01). While associations in fully adjusted models for total VLDL-P and small VLDL-P were significant in men without HIV, there were no significant associations between these particle concentrations with coronary plaque progression among men without HIV (interaction p< 0.01) (Model 2, Table 2). Conclusion Associations between lipid particle concentrations and coronary plaque progression differed between men with and without HIV, with stronger associations seen in men without HIV for total and small LDL-P. Despite having higher VLDL and lower HDL particle concentrations at baseline, these particle concentrations were only associated with plaque progression in men without HIV. Further research is needed to elucidate HIV specific factors for plaque progression to tailor risk reduction strategies.

Sex differences in the associations of HDL particle concentration and cholesterol efflux capacity with incident coronary artery disease in type 1 diabetes: The RETRO HDLc cohort study

In type 1 diabetes, women lose their relative protection (compared to men) against coronary artery disease (CAD), while high-density lipoprotein cholesterol (HDL-C) is less strongly associated with lower CAD risk in women. We aimed to assess whether sex differences in the HDL particle concentration (HDL-P) and cholesterol efflux capacity (CEC) association with CAD may explain these findings. HDL-P (calibrated differential ion mobility analysis) and total and ATP binding cassette transporter A1 (ABCA1)-specific CEC were quantified among 279 men and 271 women with type 1 diabetes (baseline mean age 27·8 years; diabetes duration, 19·6 years). Clinical CAD was defined as CAD death, myocardial infarction and/or coronary revascularization. Women had higher large HDL-P levels and marginally lower concentrations of small HDL-P and ABCA1-specific CEC than men. No sex differences were observed in extra-small HDL-P, medium HDL-P and total CEC. During a median follow-up of 26 years, 37·6 % of men and 35·8 % of women developed CAD (p = 0·72). In multivariable Cox models stratified by sex (pTotal HDL-P x sex interaction=0·01), HDL-P was negatively associated with CAD incidence in both sexes. However, associations were stronger in men, particularly for extra-small HDL-P (hazard ratio (HR)men=0·11, 95 % confidence interval (CI): 0·04-0·30; HRwomen=0·68, 95 % CI: 0·28-1·66; pinteraction=0·001). CEC did not independently predict CAD in either sex. Despite few absolute differences in HDL-P concentrations by sex, the HDL-P - CAD association was weaker in women, particularly for extra-small HDL-P, suggesting that HDL-P may be less efficient in providing atheroprotection in women and perhaps explaining the lack of a sex difference in CAD in type 1 diabetes.

THU335 Hyperinsulinemia Is Associated With An Atherogenic Lipoprotein Profile In Humans With Selective Insulin Resistance And An Atheroprotective Profile In Humans With Non-selective Insulin Resistance

Abstract Disclosure: D. Walzer: None. M. Lightbourne: None. M. Walter: None. Y. Dai: None. R.D. Shamburek: None. R.J. Brown: None. Insulin resistance (IR), a major risk factor for cardiovascular disease (CVD), leads to hyperglycemia and dyslipidemia. In obesity-associated IR, dyslipidemia attributed to increased stimulation of hepatic lipogenesis by insulin, whereas IR in glucoregulatory pathways leads to hyperglycemia. This dichotomy in insulin signaling pathways is termed selective IR. Lipodystrophy syndromes (LD) are rare conditions of severe, selective IR in which, like obesity, hyperinsulinemia with excess insulin receptor signaling is thought to cause high triglycerides (TG) & low HDL. By contrast, in the rare condition of insulin receptor pathogenic variants (INSR) (nonselective IR) lack of insulin signaling through its receptor despite hyperinsulinemia leads to low TG and high HDL. Rodents with hepatic INSR k/o have an atherogenic lipid profile, but the lipoprotein profile in humans with INSR is unknown. Factors influencing atherogenicity of lipoprotein particles, including cholesteryl ester transfer protein (CETP) activity and adiponectin, have not been explored in these human models of severe selective vs. non-selective IR. We characterized atherogenicity of lipoprotein particles and factors influencing these particles in subjects with LD matched 2:1 with subjects with INSR based on age and sex. All subjects had fasting lipoprotein profiles by NMR spectroscopy, apolipoproteins AI (ApoI) and B (ApoB), total adiponectin by ELISA, and CETP activity by fluorometric assay. Subjects with LD (N=24, 75% female; 8 generalized, 16 partial) had a more atherogenic lipoprotein profile vs INSR (N=12, 50% female; 6 homozygous, 6 heterozygous), with 45-fold higher large TRLP, 20-fold higher medium TRLP, 15-fold higher very small TRLP (representing IDL), 3-fold higher small LDLP, 4-fold lower large HDLP, 1.7—fold higher ApoB, and 1.4—fold lower ApoAI (p <0.05 for all). CETP activity was comparable in INSR and LD. Adiponectin was 5.9- fold lower in LD vs INSR (p <0.0001). Among all subjects, adiponectin was positively associated with HDL-C, large HDLP, HDL size, and ApoA-I (p=0.001), and negatively correlated with TRLP number & size, small LDLP, and very small TRLP (p<0.0001). Selective IR in LD is associated with an atherogenic lipoprotein particle profile. By contrast, non-selective IR in INSR is associated with an atheroprotective profile, which differs from rodent models. These divergent lipid phenotypes are not explained by different CETP activity. Although preclinical studies suggest that adiponectin promotes a favorable lipoprotein profile consistent with our observed associations, a causal link in humans is not supported by Mendelian randomization studies or rare ADIPOQ gene deletions. Overall, these findings suggest a key role of selective insulin resistance in the development of an atherogenic lipid profile. Further studies are needed to see if this profile leads to increased CVD risk. Presentation: Thursday, June 15, 2023

Association of Lipoprotein Subfractions With Presence and Severity of Coronary Artery Disease in Patients Referred for Coronary Angiography

Lipoprotein subfractions (LS) can be used for better risk stratification in subjects deemed not at high risk for coronary artery disease (CAD). In this study, we evaluated the correlation between LS with CAD presence and severity. This is a prospective case-control study of 157 patients referred for coronary angiography who were not on lipid-lowering therapy and had LS measured by nuclear magnetic resonance spectroscopy. Synergy between PCI with Taxus and Cardiac Surgery (SYNTAX) scores were calculated to estimate CAD severity. Univariate and multivariable regression analysis was performed to determine correlation of LS with CAD presence and severity and acute coronary syndrome (ACS). There was significant association of certain LS (positive for total low-density lipoprotein particle [LDL-P], small LDL-P and apolipoprotein B, negative for large high-density lipoprotein particle [HDL-P] and apolipoprotein A1 [ApoA1]) with the presence of obstructive CAD and CAD severity. Small LDL-P and HDL-P were still predictive for obstructive CAD after adjusting for traditional risk factors, 10-year atherosclerotic cardiovascular disease risk score and in those with low-density lipoprotein cholesterol <100mg/100ml. Total LDL-P and ApoA1 were predictive of CAD severity on multivariable analysis. Higher small LDL-P and lower large HDL-P were associated with ACS presence, although only large HDL-P had a significant inverse correlation with ACS on adjusted analysis (odds ratio 0.74 95% confidence interval 0.58, 0.95) In conclusion, in our cohort of patients referred for coronary angiography, total LDL-P, small LDL-P, and apolipoprotein B had significant direct correlation, and large HDL-P and ApoA1 had significant inverse correlation with obstructive CAD and CAD severity.

327-OR: Smaller HDL Particles and ABCA1 Cholesterol Efflux Capacity Predict Incident Proliferative Retinopathy Only among Men with Type 1 Diabetes

Clinical studies have provided evidence for a potential role of dyslipidemia in the development of retinopathy in type 1 diabetes. Existing evidence, however, is generally based on conventional lipid analysis and/or cross-sectional study designs. We therefore assessed the prospective association of HDL particle concentration (HDL-P) and cholesterol efflux capacity (CEC) with incident proliferative diabetic retinopathy (PDR) in a cohort of childhood-onset type 1 diabetes. HDL-P (calibrated differential ion mobility analysis) and total and ABCA1-specific CEC (validated cell-based assays) were quantified in 186 men and 185 women with type 1 diabetes free of PDR (stereo fundus photography) at baseline (mean age 25.6 years; diabetes duration, 17.1 years). Women had higher large HDL-P than men; the concentrations of extra-small, small and medium HDL-P as well as both total and ABCA1 CEC were similar by sex. During a median follow-up of 28 years, 108 men and 100 women developed PDR. In multivariable Cox models stratified by sex, HDL-C did not predict PDR incidence in either sex. However, in addition to increased HbA1c, non-HDL-C, white blood cell count and albumin excretion rate, increased extra-small (HR=0.25, 95% CI=0.09-0.67) and small (HR=0.72, 95% CI=0.55-0.94) HDL-P concentrations and ABCA1 CEC (HR=0.80, 95% CI=0.64-0.998) negatively predicted PDR in men but not women, among whom HbA1c, hypertension and white blood cell count were the only consistent significant predictors of PDR. In conclusion, while extra-small and small HDL-P concentrations and ABCA1 CEC did not differ by sex in type 1 diabetes, they only predicted incident PDR in men, a finding similar to our previously reported results for coronary artery disease. Further research is warranted to better understand the role of HDL in the pathophysiology of PDR and why this appears to differ by sex in type 1 diabetes. Disclosure T.Costacou: None. R.G.Miller: None. T.J.Orchard: None. Funding National Institutes of Health (R01HL130153, R01DK034818)

Association of lipid profile with obesity among breast cancer survivors: a cross-sectional study

BackgroundThe role of lipid metabolism in obesity and cancer manifestations cannot be underestimated, but whether alterations in lipid metabolism can manipulate the vasculature to promote obesity among breast cancer (BC) survivors is yet to be clearly understood. This study quantified plasma lipid and particle sizes using high-throughput proton (1H) nuclear magnetic resonance (NMR) and tested their associations with obesity among breast cancer (BC) survivors.MethodsA total of 348 (225 premenopausal and 123 postmenopausal) BC survivors enrolled from five hospitals in Korea were included. We assessed thirty-four plasma lipid biomarkers using 1H NMR, and obesity status was defined as a body mass index (BMI) of 25 kg/m2 or greater. Generalized linear and logistic regression models were applied to estimate the least-square means of BMI (kg/m2) and odds ratio (OR)s of obesity, respectively, and the corresponding 95% confidence interval (CI)s across plasma lipid levels.ResultsMean (SD) values of BMI was 23.3 (3.2) kg/m2 and 90 (25.9%) had BMI of ≥ 25 kg/m2. BMI levels increased with increasing total triglycerides (TG), TG in lipoproteins and very-low-density lipoprotein (VLDL) subfractions. However, BMI levels decreased with increasing tertiles of high-density lipoprotein (HDL)-cholesterol (C) and HDL particle size (HDL-p). Similar associations were observed in the logistic regression models. The increasing and decreasing BMI trends with TG and HDL profiles respectively were predominantly limited to premenopausal BC survivors.ConclusionsIncreasing levels of plasma total TG and TG in lipoproteins were associated with increasing levels of BMI among premenopausal BC survivors. High HDL-C levels and large HDL-p were inversely associated with obesity among premenopausal BC survivors. Due to the cross-sectional design of this study, longitudinal studies are necessary to examine the association between obesity and lipid profile among BC survivors.

Abstract 118: Cholesteryl Ester Transfer Protein Overrides The Protective Effect Of APOA1 On Arterial APOB Lipoprotein Trapping And Atherosclerosis Progression In A Mouse Model Of Type 1 Diabetes

Despite the benefits of LDL-cholesterol-reducing medications, patients with type 1 diabetes (T1D) continue to have an increased risk of incident CVD. Preclinical and clinical observations indicate that triglyceride-rich lipoproteins (TRLs) and their remnants may contribute significantly to CVD risk in T1D. Recently, we have shown that diabetes increases levels of atherogenic TRL remnants and that improvement of remnant clearance halts atherosclerosis in a mouse model of T1D. Cholesteryl ester transfer protein (CETP), which is normally absent in mice, links metabolism of TRLs to that of HDL by mediating the transfer of cholesteryl ester from HDL to VLDL and other APOB-containing lipoproteins in exchange for triglycerides. We hypothesized that CETP impairs the atheroprotective effects of APOA1 by altering TRL and HDL metabolism in diabetes. To test this hypothesis, we developed a virally-induced T1D mouse model expressing the human APOA1 transgene ( APOA1 Tg , Ldlr –/– ). Cohorts of these mice were injected with a liver-targeted adeno-associated virus to express human CETP, and the effects on lipoproteins, plasma apolipoproteins, HDL particle concentrations (HDL-P), and atherosclerosis in the presence and absence of diabetes were determined. This mouse model exhibits an HDL profile similar to humans, with small, medium and large HDL-P, whereas wildtype ( Ldlr -/- ) littermates have only one sized HDL-P. Expression of the APOA1 transgene significantly suppressed diabetes-accelerated necrotic core expansion and accumulation of APOB and APOE in the aortic sinus (compared to wildtype Ldlr -/- mice), while CETP impaired the protective effect of APOA1 on these parameters in diabetic APOA1 Tg , Ldlr –/– mice (n= 22-30, p &lt; 0.05). Further characterization of plasma lipoproteins and apolipoproteins by targeted mass spectrometry, FPLC and differential ion mobility analysis indicated that CETP leads to smaller TRL remnant particles, increases triglyceride content in HDL, lower levels of plasma APOA1 and reduction in large HDL-P under diabetic conditions (n= 8-10, p &lt; 0.05). Our results are consistent with the proposal that inhibition of CETP might be cardioprotective in the setting of T1D and highlight the close links between TRL and HDL metabolism in diabetes.

The Relationship Between Lipoproteins and Insulin Sensitivity in Youth With Obesity and Abnormal Glucose Tolerance.

Youth with obesity and abnormal glucose tolerance have an increased risk for atherosclerosis but the relative contributions of insulin resistance and hyperglycemia to dyslipidemia and the development of subclinical atherosclerosis are unknown. This work aims to determine the association between insulin resistance, dyslipidemia, and carotid intimal thickness (cIMT) in adolescents with normal and abnormal glucose tolerance. An observational cohort study in 155 youth: 44 obese insulin sensitive (OIS; fasting insulin ≤ 20 µM/mL, body mass index [BMI] ≥ 95th percentile), 35 obese insulin resistant (OIR; fasting insulin > 20 µM/mL, BMI ≥ 95th percentile), 34 obese abnormal glucose tolerant (AGT; BMI ≥ 95th percentile), and 42 Lean (BMI 5th-85th percentile). Lipids, lipoprotein particle size and concentration (-P), insulin sensitivity (SI an intravenous glucose test), and CMIT were compared using linear models adjusted for age, race/ethnicity, biological sex, and Tanner stage. Lipid/lipoprotein profile and CMIT were reevaluated in a subset after 2 years. Compared to OIS and Lean, OIR and AGT had elevated triglycerides and low high-density lipoprotein cholesterol (HDL-C) but similar total cholesterol and low-density lipoprotein cholesterol (LDL-C). Among OIS, OIR, AGT, lower SI was associated with atherogenic lipids (higher triglycerides, LDL-C, non-HDL-C, and lower HDL-C) and lipoproteins (higher total LDL-P and small HDL-P, and lower large HDL-P). There was a steeper decline in the association of SI with HDL-C and large HDL-P in AGT compared with OIR and OIS. cIMT was comparable across groups and inversely correlated with SI, with no change after 2 years. Among youth with obesity, insulin resistance was associated with an atherogenic lipoprotein/lipid profile and cIMT, regardless of glucose tolerance status. Insulin resistance in AGT youth was associated with a shift to smaller HDL-P compared to normoglycemic youth with obesity. Alterations in HDL-P metabolism may be early adverse manifestations of hyperglycemia in youth with obesity.

Caregiving stress and burden associated with cardiometabolic risk in family caregivers of individuals with cancer

Chronic stress is a well-established risk factor for cardiometabolic disease. Caregiving for individuals with cancer is perceived as a chronic stressor yet research on the risk for cardiometabolic disease in this population, opposed to the elderly and those with Alzheimer’s disease, is limited. Additionally, few studies have explored the early physiological changes that occur in family caregivers suggesting an elevated risk for illness. This cross-sectional study was designed to examine levels of cardiometabolic risk biomarkers and their correlates in caregivers of patients with colorectal cancer. Caregivers completed questionnaires that measure exposures to stress and vulnerability factors, psychological distress, and health habits as potential correlates. Traditional lipid and nontraditional lipoprotein particle biomarkers (e.g. concentration and size for all lipoprotein classes) were assayed from blood serum. Caregivers (N = 83, mean age = 49.8, 73% female) displayed levels of cardiometabolic biomarkers that suggest an elevated risk for cardiometabolic disease. Caregivers who were Hispanic, married, highly educated, employed, reported more hours spent caregiving daily, experienced higher caregiver burden associated with the lack of family support and impact on schedule, and psychological distress, demonstrated an elevated risk for cardiometabolic disease; primarily determined by nontraditional lipid biomarkers – large TRL-P, LDL-P, small HDL-P, large HDL-P, TRL-Z, LDL-Z and HDL-Z. These findings suggest that traditional lipid biomarkers may not be robust enough to detect early physiological changes associated with cardiometabolic disease risk in family caregivers. Moreover, findings reiterate the importance of assessing caregiver burden and providing evidence-based interventions to manage caregiving stress with the potential to improve caregivers’ cardiometabolic health.

Effects of a low-carbohydrate diet on insulin-resistant dyslipoproteinemia—a randomized controlled feeding trial

ABSTRACTBackgroundCarbohydrate restriction shows promise for diabetes, but concerns regarding high saturated fat content of low-carbohydrate diets limit widespread adoption.ObjectivesThis preplanned ancillary study aimed to determine how diets varying widely in carbohydrate and saturated fat affect cardiovascular disease (CVD) risk factors during weight-loss maintenance.MethodsAfter 10–14% weight loss on a run-in diet, 164 participants (70% female; BMI = 32.4 ± 4.8 kg/m2) were randomly assigned to 3 weight-loss maintenance diets for 20 wk. The prepared diets contained 20% protein and differed 3-fold in carbohydrate (Carb) and saturated fat as a proportion of energy (Low-Carb: 20% carbohydrate, 21% saturated fat; Moderate-Carb: 40%, 14%; High-Carb: 60%, 7%). Fasting plasma samples were collected prerandomization and at 20 wk. Lipoprotein insulin resistance (LPIR) score was calculated from triglyceride-rich, high-density, and low-density lipoprotein particle (TRL-P, HDL-P, LDL-P) sizes and subfraction concentrations (large/very large TRL-P, large HDL-P, small LDL-P). Other outcomes included lipoprotein(a), triglycerides, HDL cholesterol, LDL cholesterol, adiponectin, and inflammatory markers. Repeated measures ANOVA was used for intention-to-treat analysis.ResultsRetention was 90%. Mean change in LPIR (scale 0–100) differed by diet in a dose-dependent fashion: Low-Carb (–5.3; 95% CI: –9.2, –1.5), Moderate-Carb (–0.02; 95% CI: –4.1, 4.1), High-Carb (3.6; 95% CI: –0.6, 7.7), P = 0.009. Low-Carb also favorably affected lipoprotein(a) [–14.7% (95% CI: –19.5, –9.5), –2.1 (95% CI: –8.2, 4.3), and 0.2 (95% CI: –6.0, 6.8), respectively; P = 0.0005], triglycerides, HDL cholesterol, large/very large TRL-P, large HDL-P, and adiponectin. LDL cholesterol, LDL-P, and inflammatory markers did not differ by diet.ConclusionsA low-carbohydrate diet, high in saturated fat, improved insulin-resistant dyslipoproteinemia and lipoprotein(a), without adverse effect on LDL cholesterol. Carbohydrate restriction might lower CVD risk independently of body weight, a possibility that warrants study in major multicentered trials powered on hard outcomes. The registry is available through ClinicialTrials.gov: https://clinicaltrials.gov/ct2/show/NCT02068885.

Abstract 9768: Relationship of Atherogenic Lipoproteins with Insulin Resistance and Carotid Intimal Thickness in Youth at Risk for Cardiovascular Disease

Introduction: Youth with obesity and abnormal glucose tolerance (AGT) have an atherogenic lipoprotein (Lp) profile (small dense HDL and small LDL) and an increased risk for atherosclerotic disease, but the relative contributions of hyperglycemia and insulin resistance to the development of subclinical atherosclerosis in youth are not well defined. Hypothesis: Atherogenic Lp concentrations (ApoB, small LDLp, small HDLp) are associated with lower insulin sensitivity (Si) and greater carotid intimal thickness (cIMT), irrespective of glycemic status. Methods: In 155 youth with obesity (14.5±1.4y (mean±SD), 50% female; 42 lean (LC: BMI 25-85%ile), 44 insulin sensitive (OIS, fasting insulin ≤20μM/mL, BMI≥95%ile), 35 insulin resistant (OIR; fasting insulin&gt;20μM/mL, BMI≥95%ile) and 34 with AGT (23 prediabetes, 11 type 2 diabetes) we compared a standard lipid panel and Lp size and number. Linear regressions were used to test the associations between lipids/ NMR-derived Lp with Si index derived from a minimal model during an intravenous glucose test. cIMT was determined by ultrasonography. In a subset of 56 youth (21 LC, 19 OIS, 10 OIR, and 7 AGT) we explored the change in Si with the change in Lp and cIMT after 2 years. Results: OIR and AGT had higher triglycerides and lower HDL compared to LC, P &lt;0.01. Total cholesterol, LDL, and cIMT were comparable among all youth. ApoB, total triglyceride-rich Lp, LDLp and small LDLp) were similar in OIS, OIR, and AbGT and higher compared to LC. Among adolescents with obesity, Si was inversely associated with ApoB (β=-0.016), total LDLp (β=-0.91), small HDLp (β=-0.11) and cIMT (β= -2.99), all P &lt;0.001. There was no effect modification by obesity group. LnSi was associated with total HDL (β=1.30), large HDLp (β= 0.23) and small HDLp (β=-0.11), all P &lt;0.01) with steeper associations between AGT vs OIR and AGT vs OIS. After 2 years, the change in insulin sensitivity was not associated with changes in lipoproteins or cIMT. Conclusions: Among youth with obesity, insulin resistance was associated with atherogenic lipoproteins and cIMT, regardless of glucose tolerance status. Alterations in HDL particle number and size were distinct early manifestations that were observed in youth with AGT compared to their peers.

Lipoprotein Particle Size Distributions in Response to a 6-Week Dietary Intervention Using Different Dairy Food Matrices Including Cheese and Butter

Abstract Objectives Most dietary guidelines recommend saturated fat (SFA) intakes to be &amp;lt; 10% of total energy intake, since SFA increase low-density lipoprotein cholesterol (LDL-c) levels, a known risk factor for cardiovascular disease (CVD). However, within LDL-c, small, dense LDL particles are more strongly related to CVD risk than large buoyant particles, and response to SFA vary for different foods. Dairy fat, when eaten as cheese, significantly lowers total cholesterol compared to butter. Here, we aimed to test the effect of the cheese matrix on lipoprotein particle size distribution response in overweight adults aged ≥ 50 years. Methods In this secondary analysis of a 6-week randomised parallel intervention(1); participants received ∼40g dairy fat in 1 of 4 treatments: (A) 120 g of full-fat cheddar cheese (FFCC); (B) reduced-fat cheese plus butter (RFC + B); (C) butter, calcium caseinate powder, and calcium supplement (CaCO3) (BCC); or (D) 120 g FFCC as per (A). Fasting EDTA blood samples at wk. 0 (baseline) and wk. 6 were analysed for lipoprotein particle size distribution via nuclear magnetic resonance (NMR) spectroscopy. To examine extremes in response, those with greatest reduction in LDL-c (n = 15, ‘positive’ responders) were compared to those with the greatest increase in LDL-c (n = 15, ‘negative’ responders). Results Correlation analyses between the change in cholesterol levels and change in particle size distribution suggest a relationship between change in LDL-c, HDL-c, and corresponding particle sizes, which differs dependent on the dairy fat matrix. The correlation of LDL-c and LDL particle (LDL-p) concentration weakened as less fat was present within a cheese matrix, as LDL-c decreased so did total LDL-p, due to larger LDL particles. The positive responders displayed a stronger relationship between change in cholesterol and lipoprotein levels, with the changes in cholesterol driven by the large LDL-p and large HDL-p. Conclusions Lipoprotein particle distribution is correlated with change in cholesterol levels after a 6-week intervention of dairy fat. The changes in LDL-c and HDL-c were driven by the less atherogenic, large LDL-p and large HDL-p which are inversely associated with CVD risk. The overall response in LDL-p to SFA appears to vary, dependent on the dairy food matrix in which the fat was eaten. Funding Sources Food for Health Ireland (FHI). Enterprise Ireland.

Discordance Between Ldl Cholesterol Versus Particle Concentration And The Cardiovascular Risk Factor Profile

Although low-density lipoprotein cholesterol (LDL-C) levels have been associated with cardiovascular disease (CVD) risk, subjects with well controlled LDL-C are still at considerable residual risk for CVD. Alternative measures such as particle concentration of LDL (LDL-P) may be clinically useful for fully characterizing LDL associated risk. PURPOSE: To compare CVD risk factor profiles among groups of people with discordant levels of LDL-C versus LDL-P concentration in the HERITAGE Family Study. METHODS: Standard lipid panels and lipoprotein subclass profiles via nuclear magnetic resonance (NMR) spectroscopy were measured among 715 participants (34% Black, 55% Female). LDL-C and LDL-P values ≥ the median value were considered high and values < median were considered low. Four exclusive LDL-C/LDL-P groups were identified for LDL from these base categories: 1) low/low (< median for both LDL-C and LDL-P), 2) low/high (< median for LDL-C, ≥ median for LDL-P), 3) high/low, and 4) high/high. Cross-sectional associations between baseline LDL discordance group and CVD risk factors were assessed via multivariable linear regression. All models were adjusted for age, race, and sex. RESULTS: Sixty four (9.0%) participants were discordant with high LDL-C/low LDL-P, while 61 (8.5%) were discordant with low LDL-C/high LDL-P. Both concordant groups (low LDL-C/low LDL-P, high LDL-C/high LDL-P) were composed of 295 participants each (41.3%). Main effects (p<0.05) of LDL discordant group were found for the following outcomes: triglycerides, HDL-C, HDL-P size and small and large HDL-P concentration, percent body fat, maximal oxygen uptake, fasting insulin, lipoprotein lipase activity, testosterone, GlycA, and C-reactive protein. In general, groups with lower LDL-P had more favorable CVD risk factor profiles relative to high LDL-P groups. CONCLUSIONS: In general, low LDL-P levels were associated with favorable CVD risk factor profiles regardless of LDL-C levels.

Effects of a Low-Carbohydrate Diet on Cardiometabolic Risk Factors During Weight-Loss Maintenance: A Randomized Controlled Feeding Trial

Abstract Objectives To compare effects of diets varying in carbohydrate (carb) and fat on plasma lipids and lipoprotein subfractions. Methods Participants (N = 164, 70% female, 18–65 y, BMI ≥ 25 kg/m2) achieved 10–14% weight loss on a run-in diet and then were randomized to 3 test diets for 20 weeks of weight-loss maintenance. Percentages of total energy from carb-fat-protein for high-, moderate-, and low-carb diets were 60-20-20 (HI), 40-40-20 (MOD), and 20–60-20 (LO). Relative amounts of added sugar (15% total carb) and saturated fat (35% total fat) were fixed across diets. Plasma was collected at START (post-weight loss) and END of trial. The primary outcome for this ancillary study was lipoprotein insulin resistance (LPIR) – a 6-component weighted score of triglyceride-rich, high-density, and low-density lipoprotein particle (TRL-P, HDL-P, LDL-P) sizes and subfraction concentrations (large/very large TRL-P, large HDL-P, small LDL-P) (NMR spectroscopy, LabCorp). Other outcomes included large LDL-P concentration, triglycerides (TG), and cholesterol (HDL-C, LDL-C). Means (±SE) and END–START changes (mean [95% CI]) were constructed and compared from repeated measures ANOVA. Results Retention was 90% and 147 participants provided evaluable data, with no difference in body weight by diet after randomization. LPIR was 32.6 ± 1.5 at START. Change in LPIR differed by diet (P = 0.009): LO (−5.3 [−9.2, −1.5]), MOD (−0.02 [−4.1, 4.1]), HI (3.6 [−0.6, 7.7]). Diet effects favoring LO compared to HI were observed for large/very large TRL-P (P = 0.005), large HDL-P (P = 0.045), TG (P = 0.006), and HDL-C (P = 0.04). There were no mean differences between diets for particle sizes, LDL-P subfraction concentrations, and LDL-C (START: 79.3 ± 1.8 mg/dL; END–START: HI, 8.2 [4.2, 12.2]; MOD, 11.7 [7.8, 15.7]; LO, 10.0 [6.3, 13.7]). Conclusions With 3-fold higher saturated fat content (21% vs 7% total energy), a low- vs high-carb diet improved LPIR, a biomarker of diabetes risk, and several other components of the metabolic syndrome, with no adverse effects on LDL-P or LDL-C. These results from a large feeding study suggest that carb restriction may help prevent cardiometabolic disease independent of body weight. Funding Sources Nutrition Science Initiative (gifts from Arnold Ventures and Robert Lloyd Corkin Charitable Foundation), New Balance Foundation, Many Voices Foundation, Blue Cross Blue Shield.

Association of particles of lipoprotein subclasses with arterial stiffness in a high-risk working population: the Baptist Employee Healthy Heart Study (BEHHS)

BackgroundArterial stiffness is an independent predictor of cardiovascular disease (CVD) morbidity and mortality. A risk factor-independent association of arterial stiffness with traditional lipids has been described extensively, but it is still unclear whether an independent relationship exists between arterial stiffness and particles of lipoprotein subclasses.MethodsThe Baptist Employee Healthy Heart Study (BEHHS) is a lifestyle intervention study examining the effects of web-based programs on reducing CVD risk in high-risk persons. Participants had their brachial arterial augmentation index (AI, a measure arterial stiffness) assessed using the EndoPAT 2000 device. Cardio IQ™ ion mobility lipoprotein fractionation was utilized for measurement of particles of lipoprotein subclasses.ResultsThe population consisted of 182 participants, (74% women, 49% Hispanic) with a mean age of 52 ± 9 years. There was a significant trend association between quartiles of AI and total cholesterol, HDL-c, large LDL-p, small IDL-p, large IDL-p, and all subclasses of HDL particles (total HDL-p, small HDL-p, and large HDL-p). In logistic regression analysis, only HDL-c, total LDL-p, large LDL-p, small IDL-p, large IDL-p, total HDL-p, small HDL-p, and large HDL-p demonstrated significant independent association with AI.ConclusionSeveral lipoprotein subclasses demonstrate independent significant associations with arterial stiffness. A safe and relatively inexpensive blood test may be useful in identifying subclinical atherosclerosis process in a relatively young high CVD risk population.Trial registrationClinicalTrials.gov, NCT01912209. Registered July 31, 2013

Association of high-density lipoprotein particle concentration with cardiovascular risk following acute coronary syndrome: A case-cohort analysis of the dal-Outcomes trial

High-density lipoprotein cholesterol (HDL-C) concentration is inversely related to risk of major adverse cardiovascular events (MACE) in epidemiologic studies but is a poorer predictor of MACE in patients with established coronary heart disease. HDL particle concentration (HDLP) has been proposed as a better predictor of risk. We investigated whether HDLP is associated with risk of MACE after acute coronary syndrome (ACS). The dal-Outcomes trial compared the CETP inhibitor dalcetrapib with placebo in patients with recent ACS. In a nested case-cohort analysis, total, large, medium, and small HDLPs were measured by nuclear magnetic resonance spectroscopy at baseline (4-12 weeks after ACS) in 476 cases with MACE and 902 controls. Hazard ratios (HRs; case-control) for 1-SD increment of HDLP or HDL-C at baseline were calculated with and without adjustment for demographic, clinical, laboratory, and treatment variables. Similarly, HRs for MACE were calculated for changes in HDLP or HDL-C from baseline to month 3 of assigned treatment. Over median follow-up of 28 months, the risk of MACE was not associated with baseline HDLP (adjusted HR = 0.98, 95% CI = 0.84-1.15, P = .81), any HDLP subclass, or HDL-C. Dalcetrapib increased HDL-C and total, medium, and large HDLP and decreased small HDLP but had no effect on MACE compared with placebo. There were no association of risk of MACE with change in HDLP or HDL-C and no interaction with assigned study treatment. Neither baseline HDLP nor the change in HDLP on treatment with dalcetrapib or placebo was associated with risk of MACE after ACS.

Greater IL-6, D-dimer, and ICAM-1 Levels Are Associated With Lower Small HDL Particle Concentration in the Multicenter AIDS Cohort Study.

Low HDL cholesterol (HDL-C) is common in people living with HIV infection, which is associated with inflammation, and correlates with greater cardiovascular disease (CVD) risk. Particles of HDL are HDL subfractions, and in some general population studies, higher small HDL particle number (HDL-P) has been associated with lower CVD risk. The objective of this study was to determine whether HIV serostatus and systemic inflammation were associated with small HDL-P in the Multicenter AIDS Cohort Study (MACS). The MACS is composed of HIV-infected and HIV-uninfected men. Separate linear regression analyses were conducted to evaluate the associations between outcomes (small HDL-P, large HDL-P, total HDL-P, and HDL size) and variables of interest (interleukin-6 [IL-6], D-dimer, and intercellular adhesion molecule-1 [ICAM-1] levels), with adjustment for other CVD risk factors. The study population included 553 HIV-infected (88.1% on current ART) and 319 HIV-uninfected men. The mean age was 52.7 years for HIV-infected men and 55.3 years for HIV-uninfected men. In separate models of the study population, higher log IL-6 was associated with lower total and small HDL-P (P < .01 for both), independent of HIV serostatus and CVD risk factors. Similar results were seen with ICAM-1. Positive HIV serostatus was associated with lower small and total HDL-P, adjusted for inflammatory markers. Greater systemic inflammation and HIV infection both were associated with lower atheroprotective small HDL-P. This may be a potential mechanism contributing to increased cardiovascular risk among HIV-infected people.

Low cholesterol efflux capacity and abnormal lipoprotein particles in youth with type 1 diabetes: a case control study

BackgroundPatients with type 1 diabetes (T1DM) have increased mortality from cardiovascular disease (CVD). Risk factors for CVD include an elevation of LDL (LDLp) and small HDL (sHDLp) particles, and a decrease in reverse cholesterol transport i.e. HDL-cholesterol efflux capacity (CEC). Our objective was to compare lipoprotein particles and CEC between T1DM and healthy controls (HC) and to explore the associations between NMR lipid particles and cholesterol efflux.Methods78 patients with T1DM and 59 HC underwent fasting lipoprotein profile testing by NMR and measurements of CEC by cell-based method. The associations between NMR lipid particles with CEC were analyzed using multivariable linear regression models.ResultsYouth with T1DM had higher total LDLp 724 [(563–985) vs 622 (476–794) nmol/L (P = 0.011)] (Maahs et al. in Circulation 130(17):1532–58, 2014; Shah et al. in Pediatr Diabetes 16(5):367–74, 2015), sHDLp [11.20 (5.7–15.3) vs 7.0 (3.2–13.1) μmol/L (P = 0.021)], and lower medium HDLp [11.20 (8.5–14.5) vs 12.3 (9–19.4), (P = 0.049)] and lower CEC (0.98 ± 0.11% vs 1.05 ± 0.15%, P = 0.003) compared to HC. Moreover, CEC correlated with sHDLp (β = − 0.28, P = 0.045) and large HDLp (β = 0.46, P < 0.001) independent of age, sex, ethnicity, BMIz, HbA1c, hsCRP and total HDLp in the diabetic cohort.ConclusionsYouth with T1DM demonstrated a more atherogenic profile including higher sHDL and LDLp and lower CEC. Future efforts should focus on considering adding lipoprotein particles and CEC in CVD risk stratification of youth with T1DM.Trial registration Clinical Trials Registration Number NCT02275091

Abstract 390: A New Humanized Mouse Model to Study Lipid Abnormalities and HDL Function in Poorly Controlled Type 1 Diabetes Mellitus

Elevated plasma triglycerides (TG) and VLDL are often present in poorly controlled type 1 diabetes mellitus (T1DM). Furthermore, T1DM patients exhibit an increased risk of cardiovascular disease (CVD) despite normal or high HDL-cholesterol. There is a need for new mouse models to study T1DM lipid abnormalities because mice do not express cholesteryl ester transfer protein (CETP), which transfers cholesteryl ester (CE) from HDL to VLDL and other lipoproteins in exchange for TG, and because mice do not exhibit human-like HDL populations. To develop a physiologically relevant model, we crossed a virally-induced mouse model of T1DM ( Ldlr -/- ;Gp Tg ) deficient in the LDL receptor with human apolipoprotein A-I ( APOA1 ) transgenic mice. These mice (n=8-10) were injected with a liver-specific adeno-associated virus driving expression of human CETP, mimicking the human CETP activity/apoA-I ratio, and the 3 major human HDL subpopulations. Using this model ( APOA1 Tg ;Ldlr -/- ;Gp Tg ), we examined the impact of diabetes on dyslipidemia, HDL particle concentration (HDL-P), and serum HDL function. Induction of diabetes increased plasma TG and cholesterol, primarily due to an increase in VLDL, as compared with non-diabetic (ND) littermates. The dyslipidemia was associated with increases in hepatic TG content and hepatic TG production rate (2-fold over ND). Moreover, resident peritoneal macrophages from diabetic mice exhibited a 5-fold increase in CE loading, increased lipid raft content (20%), and increased Tnfa (3-fold) and Il1b mRNA (4-fold), as compared with ND littermates. In addition, T1DM mice had increased small, medium and large HDL-P (2-fold) concentrations compared with ND controls. Serum HDL from T1DM mice showed a significant increase in its cholesterol efflux capacity through both ABCA1 and ABCG1. Thus, in this humanized mouse model, poorly controlled T1DM leads to elevated plasma TG and VLDL due in part to increased hepatic TG production. This dyslipidemia is associated with higher HDL-P and an increase in serum HDL’s cholesterol efflux capacity, likely due to the increased plasma HDL-P. We have found similar changes in HDL concentration and function in humans with T1DM, suggesting that our mouse model might provide insights into CVD risk in T1DM patients.

Lipoprotein Heterogeneity Early in Pregnancy and Preterm Birth.

Background The concentration and size of lipoprotein particles are associated with race, inflammation, and disease. When triglycerides are high, as in pregnancy, lipoprotein particle size may have physiologic importance beyond conventional lipid measurements. We considered that lipoprotein particles may be related to preterm birth (PTB) and explored race differences. Materials and Methods Samples were collected at 9 weeks' gestation (22 PTB [&lt; 37 weeks]; 42 term births [≥ 37 weeks]). Lipids were assayed using standard techniques. Concentrations of high-density lipoprotein, low-density lipoprotein, and very low-density lipoprotein particles (HDL-P, LDL-P, and VLDL-P, respectively) and markers of systemic inflammation were quantified using nuclear magnetic resonance spectroscopy and related to PTB. Results Women with PTB had lower VLDL-P (− 10.66 nmol/L, p = 0.03) and higher systemic inflammation (+ 19.2 µmol/L, p = 0.02) compared with women with term births, independent of race, pre-pregnancy body mass index, and smoking. Black versus white women had lower VLDL-P and higher HDL cholesterol (both p &lt; 0.05). Race-specific results indicated that large HDL-P and inflammation (glycoprotein B) were higher with PTB versus term birth among black women only. Conclusion Women with PTB had lower VLDL-P early in pregnancy, which may represent impaired lipid response. Black–white differences in the lipoprotein profile are similar to nonpregnant adults, but race-specific lipoprotein and inflammation associations with PTB warrant further study.