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Background: Niacin as an adjunct to statin treatment to reduce cardiovascular risk is questioned., Objective: To evaluate interrelationships between the effects of niacin on mixed dyslipidemia and a spectrum of metabolic and inflammatory biomarkers., Methods: Obese, nondiabetic, hypertriglyceridemic males (n = 19) with low high-density lipoprotein-cholesterol levels received extended-release nicotinic acid for 8 weeks. Multiple biomarkers were measured using enzyme-linked immunosorbent assay, enzymatic/absorptiometric, or multiplex biochip assays. Treatment effects were determined for each variable and a differential correlation network created on the basis of univariate correlations between baseline and response to niacin treatment for all pairs of variables., Results: Extended-release niacin treatment favoured normalization of plasma lipid and apolipoprotein profile. Plasma markers of inflammation, hepatic function, cellular adhesion and proliferation, and macrophage phenotype were attenuated; however, insulin resistance increased. Differential network analysis revealed that changes in triglycerides and high-density lipoprotein-cholesterol were closely linked; equally, niacin mediated reductions in total cholesterol, apolipoprotein B, low-density lipoprotein-cholesterol and lipoprotein(a) clustered together, as did homeostatic model assessment of insulin resistance, insulin, and interleukin-6 levels. Two clusters of inflammatory markers were identified, involving (1) intercellular adhesion molecule 1 and high-sensitive C-reactive protein and (2) soluble tumor necrosis factor receptors; and novel clusters involving matrix metallopeptidase 9 and apolipoprotein E, and adiponectin and cystatin C, respectively, were equally revealed. At lower stringency, lipid and insulin resistance clusters were linked; a C-reactive protein-centered cluster linked reduction in apolipoprotein CIII to intercellular adhesion molecule 1, gamma-glutamyltransferase, soluble tumor necrosis factor receptors, and E-selectin., Conclusion: A niacin-mediated trend to normalize atherogenic mixed dyslipidemia was intimately linked to attenuation of biomarkers of inflammation, cell adhesion, hepatic dysfunction and cell proliferation, but to enhanced insulin resistance and plasma homocysteine elevation., (Copyright © 2018 National Lipid Association. Published by Elsevier Inc. All rights reserved.)

Background: Statins impact the metabolism, concentrations, composition, and function of circulating lipoproteins., Objective: We evaluated time course relationships between statin-mediated reduction in atherogenic apolipoprotein B (ApoB)-containing particles and dynamic intravascular remodeling of ApoAI-containing lipoprotein subpopulations in the mixed dyslipidemia of metabolic syndrome., Methods: Insulin-resistant, hypertriglyceridemic, hypercholesterolemic, obese males (n = 12) were treated with pitavastatin (4 mg/d) and response evaluated at 6, 42, and 180 days., Results: Reduction in low-density lipoprotein (LDL) cholesterol, ApoB, and triglycerides (TGs) was essentially complete at 42 days (-38%, -32%, and -35%, respectively); rapid reduction equally occurred in remnant cholesterol, ApoCII, CIII, and E levels (day 6; -35%, -50%, -23%, and -26%, respectively). Small dense LDLs (LDL4 and LDL5 subpopulations) predominated at baseline and were markedly reduced on treatment (-29% vs total LDL mass). Cholesteryl ester (CE) transfer protein activity and mass decreased progressively (-18% and -16%, respectively); concomitantly, TG depletion (up to -49%) and CE enrichment occurred in all high-density lipoprotein (HDL) particle subpopulations with normalization of CE/TG mass ratio at 180 days. ApoAI was redistributed from LpAI to LpAI:AII particles in HDL2a and HDL3a subpopulations; ApoCIII was preferentially depleted from LpAI:AII-rich particles on treatment., Conclusion: Overall, statin action exhibits duality in mixed dyslipidemia, as CE transfer protein-mediated normalization of the HDL CE/TG core lags markedly behind subacute reduction in elevated levels of atherogenic ApoB-containing lipoproteins. Normalization of the HDL neutral lipid core is consistent with enhanced atheroprotective function. The HDL CE/TG ratio constitutes a metabolomic marker of perturbed HDL metabolism in insulin-resistant states, equally allowing monitoring of statin impact on HDL metabolism, structure, and function., (Copyright © 2017 National Lipid Association. Published by Elsevier Inc. All rights reserved.)

The impact of statin treatment on the abnormal plasma lipidome of mixed dyslipidemic patients with metabolic syndrome (MetS), a group at increased risk of developing diabetes, was evaluated. Insulin-resistant hypertriglyceridemic hypertensive obese males (n = 12) displaying MetS were treated with pitavastatin (4 mg/day) for 180 days; healthy normolipidemic age-matched nonobese males (n = 12) acted as controls. Statin treatment substantially normalized triglyceride (-41%), remnant cholesterol (-55%), and LDL-cholesterol (-39%), with minor effect on HDL-cholesterol (+4%). Lipidomic analysis, normalized to nonHDL-cholesterol in order to probe statin-induced differences in molecular composition independently of reduction in plasma cholesterol, revealed increment in 132 of 138 lipid species that were subnormal at baseline and significantly shifted toward the control group on statin treatment. Increment in alkyl- and alkenylphospholipids (plasmalogens) was prominent, and consistent with significant statin-induced increase in plasma polyunsaturated fatty acid levels. Comparison of the statin-mediated lipidomic changes in MetS with the abnormal plasma lipidomic profile characteristic of prediabetes and T2D in the Australian Diabetes, Obesity, and Lifestyle Study and San Antonio Family Heart Study cohorts by hypergeometric analysis revealed a significant shift toward the lipid profile of controls, indicative of a marked trend toward a normolipidemic phenotype. Pitavastatin attenuated the abnormal plasma lipidome of MetS patients typical of prediabetes and T2D., (Copyright © 2015 by the American Society for Biochemistry and Molecular Biology, Inc.)