Atherosclerotic cardiovascular disease risk and small dense low-density lipoprotein cholesterol in men, women, African Americans and non-African Americans: The pooling project.

Background And Aims: Elevated small dense low-density lipoprotein-cholesterol (sdLDL-C) has been reported to be associated with increased atherosclerotic cardiovascular disease (ASCVD) risk. Our aims were to determine whether direct and calculated sdLDL-C were significant independent ASCVD risk factors in sex and race subgroups.

Methods: In a total of 15,933 participants free of ASCVD at baseline (median age 62 years, 56.

Severe acute respiratory syndrome corona virus-2 (SARS-CoV-2) serology in the vaccination era and post booster vaccination.

Background: The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic has caused over 6 million deaths world-wide. In the pre-vaccination era, we noted a 5·3% SARS-CoV-2 IgG antibody positivity rate in 81,624 subjects.

Methods: Utilizing assays for serum SARS-CoV-2 spike (S) protein antibody (Roche) and neutralizing antibody (Diazyme), both >90% IgG, we measured antibodies in 13,189 subjects in the post-vaccination era, and in 69 subjects before and 60 days after booster vaccination.

Plasma fatty acid profiles: Relationships with sex, age, and state-reported heart disease mortality rates in the United States.

Background: Fatty acids (FA) play an important role in health and heart disease risk.

Objective: We evaluated relationships of plasma FA levels, especially omega-3 FA, with sex, age, and reported heart disease mortality rates by state in a very large clinical population.

Methods: Plasma FA were measured by gas chromatography/mass spectrometry after lipid extraction in 1,169,621 fasting United States subjects grouped according to sex (56.

Corona Virus Disease-19 serology, inflammatory markers, hospitalizations, case finding, and aging.

Most deaths from severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection occur in older subjects. We assessed the utility of serum inflammatory markers interleukin-6 (IL-6), C reactive protein (CRP), and ferritin (Roche, Indianapolis, IN), and SARS-CoV-2 immunoglobulin G (IgG), immunoglobulin M (IgM), and neutralizing antibodies (Diazyme, Poway, CA). In controls, non-hospitalized subjects, and hospitalized subjects assessed for SARS-CoV-2 RNA (n = 278), median IgG levels in arbitrary units (AU)/mL were 0.

SARS-CoV-2 serology and virology trends in donors and recipients of convalescent plasma.

SARS-CoV-2 has infected millions worldwide. The virus is novel, and currently there is no approved treatment. Convalescent plasma may offer a treatment option.

Extreme hypertriglyceridemia: Genetic diversity, pancreatitis, pregnancy, and prevalence.

Background: Triglyceride (TG) concentrations >2000 mg/dL are extremely elevated and increase the risk of pancreatitis.

Objectives: We characterized five cases and two kindreds and ascertained prevalence in a reference laboratory population.

Methods: Plasma lipids and DNA sequences of LPL, GPIHBP1, APOA5, APOC2, and LMF1 were determined in cases and two kindreds.

Genetic and secondary causes of severe HDL deficiency and cardiovascular disease.

We assessed secondary and genetic causes of severe HDL deficiency in 258,252 subjects, of whom 370 men (0.33%) and 144 women (0.099%) had HDL cholesterol levels <20 mg/dl.

Diagnosis, treatment, and clinical outcomes in 43 cases with cerebrotendinous xanthomatosis.

Background: Cerebrotendinous xanthomatosis (CTX) is a rare disorder due to defective sterol 27-hydroxylase causing a lack of chenodeoxycholic acid (CDCA) production and high plasma cholestanol levels.

Objectives: Our objective was to review the diagnosis and treatment results in 43 CTX cases.

Methods: We conducted a careful review of the diagnosis, laboratory values, treatment, and clinical course in 43 CTX cases.

Differential Effects of Estrogen and Progestin on Apolipoprotein B100 and B48 Kinetics in Postmenopausal Women.

The distinct effects of the estrogen and progestin components of hormonal therapy on the metabolism of apolipoprotein (apo) B-containing lipoproteins have not been studied. We enrolled eight healthy postmenopausal women in a placebo-controlled, randomized, double-blind crossover study. Each subject received placebo, conjugated equine estrogen (CEE, 0.

The association between hypercholesterolemia and sitosterolemia, and report of a sitosterolemia kindred.

Background: Sitosterolemia is associated with increases in intestinal sterol absorption, low-density lipoprotein cholesterol (LDL-C), and cardiovascular disease risk.

Objective: We examined the relationship between hypercholesterolemia and sitosterolemia in a large population and report a new sitosterolemia case.

Methods: Plasma sterol concentrations were measured by gas chromatography/mass spectrometry, and LDL-C by direct assay.

Metabolism and proteomics of large and small dense LDL in combined hyperlipidemia: effects of rosuvastatin.

Small dense LDL (sdLDL) has been reported to be more atherogenic than large buoyant LDL (lbLDL). We examined the metabolism and protein composition of sdLDL and lbLDL in six subjects with combined hyperlipidemia on placebo and rosuvastatin 40 mg/day. ApoB-100 kinetics in triglyceride-rich lipoproteins (TRLs), lbLDL (density [] = 1.

Diagnosis and treatment of high density lipoprotein deficiency.

Low serum high density lipoprotein cholesterol level (HDL-C) <40 mg/dL in men and <50 mg/dL in women is a significant independent risk factor for cardiovascular disease (CVD), and is often observed in patients with hypertriglyceridemia, obesity, insulin resistance, and diabetes. Patients with marked deficiency of HDL-C (<20 mg/dL) in the absence of secondary causes are much less common (<1% of the population). These patients may have homozygous, compound heterozygous, or heterozygous defects involving the apolipoprotein (APO)AI, ABCA1, or lecithin:cholesterol acyl transferase genes, associated with apo A-I deficiency, apoA-I variants, Tangier disease , familial lecithin:cholesteryl ester acyltransferase deficiency, and fish eye disease.

Distinct metabolism of apolipoproteins (a) and B-100 within plasma lipoprotein(a).

Objectives: Lipoprotein(a) [Lp(a)] is mainly similar in composition to LDL, but differs in having apolipoprotein (apo) (a) covalently linked to apoB-100. Our purpose was to examine the individual metabolism of apo(a) and apoB-100 within plasma Lp(a).

Materials And Methods: The kinetics of apo(a) and apoB-100 in plasma Lp(a) were assessed in four men with dyslipidemia [Lp(a) concentration: 8.

Rosuvastatin Enhances the Catabolism of LDL apoB-100 in Subjects with Combined Hyperlipidemia in a Dose Dependent Manner.

Dose-associated effects of rosuvastatin on the metabolism of apolipoprotein (apo) B-100 in triacylglycerol rich lipoprotein (TRL, d < 1.019 g/ml) and low density lipoprotein (LDL) and of apoA-I in high density lipoprotein (HDL) were assessed in subjects with combined hyperlipidemia. Our primary hypothesis was that maximal dose rosuvastatin would decrease the apoB-100 production rate (PR), as well as increase apoB-100 fractional catabolic rate (FCR).

A novel ApoA-I truncation (ApoA-IMytilene) associated with decreased ApoA-I production.

Objective: We report a novel apolipoprotein (apo) A-I truncation (apoA-IMytilene) due to a heterozygous nonsense mutation (c.718C > T, p.Gln216*) in a 68-year-old male proband with premature coronary heart disease (CHD), corneal arcus, and very low plasma concentrations of HDL cholesterol (HDL-C) and apoA-I.

The composition and metabolism of large and small LDL.

Purpose Of Review: Decreased size and increased density of LDL have been associated with increased coronary heart disease (CHD) risk. Elevated plasma concentrations of small dense LDL (sdLDL) correlate with high plasma triglycerides and low HDL cholesterol levels. This review highlights recent findings about the metabolism and composition of LDL subfractions.

Lipoprotein(a) metabolism.

Purpose Of Review: Lipoprotein(a) [Lp(a)] is an atherogenic lipoprotein. The metabolism of this lipoprotein is still not well understood.

Recent Findings: It has long been known that the plasma concentration of Lp(a) is highly heritable, with its genetic determinants located in the apo(a) locus and regulating the rate of hepatic apo(a) production.

Effects of atorvastatin on human C-reactive protein metabolism.

Objective: Statins are known to reduce plasma C-reactive protein (CRP) concentrations. Our goal was to define the mechanisms by which CRP was reduced by maximal dose atorvastatin.

Methods: Eight subjects with combined hyperlipidemia (5 men and 3 postmenopausal women) were enrolled in a randomized, placebo-controlled double-blind, cross over study.

Linkage between C-reactive protein and triglyceride-rich lipoprotein metabolism.

Objective: Inflammation plays an important role in atherosclerosis. Elevated C-reactive protein (CRP) levels are associated with a greater risk of cardiovascular disease. Our goal was to study CRP metabolism, and to determine its relationship with lipoprotein metabolism using stable isotope methodology.

Effects of Therapeutic Lifestyle Change diets high and low in dietary fish-derived FAs on lipoprotein metabolism in middle-aged and elderly subjects.

The effects of Therapeutic Lifestyle Change (TLC) diets, low and high in dietary fish, on apolipoprotein metabolism were examined. Subjects were provided with a Western diet for 6 weeks, followed by 24 weeks of either of two TLC diets (10/group). Apolipoprotein kinetics were determined in the fed state using stable isotope methods and compartmental modeling at the end of each phase.

Effects of CETP inhibition on triglyceride-rich lipoprotein composition and apoB-48 metabolism.

Cholesteryl ester transfer protein (CETP) facilitates the transfer of HDL cholesteryl ester to triglyceride-rich lipoproteins (TRL). This study aimed to determine the effects of CETP inhibition with torcetrapib on TRL composition and apoB-48 metabolism. Study subjects with low HDL cholesterol (<40 mg/dl), either untreated (n = 9) or receiving atorvastatin 20 mg daily (n = 9), received placebo for 4 weeks, followed by torcetrapib 120 mg once daily for the next 4 weeks.

Apolipoprotein B-100-containing lipoprotein metabolism in subjects with lipoprotein lipase gene mutations.

Objective: We investigated the impact of lipoprotein lipase (LPL) gene mutations on apolipoprotein B (apoB)-100 metabolism.

Methods And Results: We studied 3 subjects with familial LPL deficiency; 14 subjects heterozygous for the LPL gene mutations Gly188Glu, Trp64Stop, and Ile194Thr; and 10 control subjects. Very-low-density lipoprotein (VLDL), intermediate-density lipoprotein (IDL), and low-density lipoprotein (LDL)-apoB-100 kinetics were determined in the fed state using stable isotope methods and compartmental modeling.

Fasting and postprandial apolipoprotein B-48 levels in healthy, obese, and hyperlipidemic subjects.

Apolipoprotein (apo) B-48 is the only specific marker of intestinal lipoproteins. We evaluated a novel enzyme-linked immunosorbent assay (ELISA) standardized with recombinant apo B-48 to measure apo B-48 in plasma and triglyceride-rich lipoproteins (TRLs, density <1.006 g/mL).

Effects of cholesteryl ester transfer protein inhibition on apolipoprotein A-II-containing HDL subspecies and apolipoprotein A-II metabolism.

This study was designed to establish the mechanism responsible for the increased apolipoprotein (apo) A-II levels caused by the cholesteryl ester transfer protein inhibitor torcetrapib. Nineteen subjects with low HDL cholesterol (<40 mg/dl), nine of whom were also treated with 20 mg of atorvastatin daily, received placebo for 4 weeks, followed by 120 mg of torcetrapib daily for the next 4 weeks. Six subjects in the nonatorvastatin cohort participated in a third phase, in which they received 120 mg of torcetrapib twice daily for 4 weeks.

Extended-release niacin alters the metabolism of plasma apolipoprotein (Apo) A-I and ApoB-containing lipoproteins.

Objective: Extended-release niacin effectively lowers plasma TG levels and raises plasma high-density lipoprotein (HDL) cholesterol levels, but the mechanisms responsible for these effects are unclear.

Methods And Results: We examined the effects of extended-release niacin (2 g/d) and extended-release niacin (2 g/d) plus lovastatin (40 mg/d), relative to placebo, on the kinetics of apolipoprotein (apo) A-I and apoA-II in HDL, apoB-100 in TG-rich lipoproteins (TRL), intermediate-density lipoproteins (IDL) and low-density lipoproteins (LDL), and apoB-48 in TRL in 5 men with combined hyperlipidemia. Niacin significantly increased HDL cholesterol and apoA-I concentrations, associated with a significant increase in apoA-I production rate (PR) and no change in fractional catabolic rate (FCR).