Lipid and Lipoprotein Biomarkers and the Risk of Ischemic Stroke in Postmenopausal Women

Abstract Background-Few studies simultaneously investigated lipids and lipoprotein biomarkers as predictors of ischemic stroke. The value of these biomarkers as independent predictors of ischemic stroke remains controversial

Inflammation predicts changes in high-density lipoprotein particles and apolipoprotein A1 following initiation of antiretroviral therapy

BACKGROUND:: The effects of HIV infection and antiretroviral therapy (ART) on usual lipid levels have been reported. The effects of initiating versus deferring ART on high-density and low-density lipoprotein particle (HDL-P and LDL-P, respectively) concentrations and apolipoprotein (Apo) levels are not well described. METHODS:: In a subgroup of participants not taking ART at study entry who were randomized in the Strategies for Management of Antiretroviral Therapy (SMART) trial to immediately initiate ART (\u27viral suppression group\u27) or to defer it (\u27drug conservation group\u27), lipoprotein particle concentrations and ApoA1 and ApoB levels were measured at baseline and at 2 and 6 months following randomization. RESULTS:: Compared with drug conservation group (n = 126), HDL-P and ApoA1 levels increased among viral suppression participants (n = 128) after starting ART. At 6 months, viral suppression participants had 13% higher total HDL-P (P \u3c 0.001) and 9% higher ApoA1 (P \u3c 0.001). LDL-P, very low density lipoprotein particle, and ApoB did not differ significantly between the viral suppression and drug conservation groups. Among viral suppression participants, predictors of HDL-P and ApoA1 increases included baseline levels of high-sensitivity C-reactive protein (hsCRP) and interleukin 6 (IL-6), but not HIV RNA level, CD4 cell count, or traditional cardiovascular disease risk factors. The effect of starting ART on changes in HDL-P and ApoA1 was greater for those with higher versus lower baseline levels of IL-6 (P = 0.001 and 0.08, respectively, for interaction) or hsCRP (P = 0.01 and 0.04, respectively, for interaction). CONCLUSION:: HDL-P and ApoA1 increase following ART initiation, to a degree that depends on the degree of inflammation present at entry. These findings suggest that activation of inflammatory pathways contribute to HIV-associated changes in HDL. © 2011 Wolters Kluwer Health Lippincott Williams & Wilkins

Effects of the BET-inhibitor, RVX-208 on the HDL lipidome and glucose metabolism in individuals with prediabetes: A randomized controlled trial

AIMS: High-density lipoprotein (HDL) and apolipoprotein A-I (apoA-I) can modulate glucose metabolism through multiple mechanisms. This study determined the effects of a novel bromodomain and extra-terminal (BET) inhibitor (RVX-208) and putative apoA-I inducer on lipid species contained within HDL (HDL lipidome) and glucose metabolism. MATERIALS AND METHODS: Twenty unmedicated males with prediabetes received 100mg b.i.d. RVX-208 and placebo for 29-33days separated by a wash-out period in a randomized, cross-over design trial. Plasma HDL-cholesterol and apoA-I were assessed as well as lipoprotein particle size and distribution using NMR spectroscopy. An oral glucose tolerance test (OGTT) protocol with oral and infused stable isotope tracers was employed to assess postprandial plasma glucose, indices of insulin secretion and insulin sensitivity, glucose kinetics and lipolysis. Whole plasma and HDL lipid profiles were measured using mass spectrometry. RESULTS: RVX-208 treatment for 4weeks increased 6 sphingolipid and 4 phospholipid classes in the HDL lipidome (p 640.05 versus placebo), but did not change conventional clinical lipid measures. The concentration of medium-sized HDL particles increased by 11% (P=0.01) and small-sized HDL particles decreased by 10% (P=0.04) after RVX-208 treatment. In response to a glucose load, after RVX-208 treatment, plasma glucose peaked at a similar level to placebo, but 30min later with a more sustained elevation (treatment effect, P=0.003). There was a reduction and delay in total (P=0.001) and oral (P=0.003) glucose rates of appearance in plasma and suppression of endogenous glucose production (P=0.014) after RVX-208 treatment. The rate of glucose disappearance was also lower following RVX-208 (P=0.016), with no effect on glucose oxidation or total glucose disposal. CONCLUSIONS: RVX-208 increased 10 lipid classes in the plasma HDL fraction, without altering the concentrations of either apoA-I or HDL-cholesterol (HDL-C). RVX-208 delayed and reduced oral glucose absorption and endogenous glucose production, with plasma glucose maintained via reduced peripheral glucose disposal. If sustained, these effects may protect against the development of type 2 diabetes