Determination of lipoprotein particle size and number using advanced lipoprotein tests (ALTs) is of particular importance to improve cardiovascular risk prediction. Here we present the Liposcale test, a novel ALT based on 2D diffusion-ordered 1H NMR spectroscopy. Our method uses diffusion coefficients to provide a direct measure of the mean particle sizes and numbers. Using 177 plasma samples from healthy individuals and the concentration of apolipoprotein B and A from isolated lipoprotein fractions our test showed a stronger correlation between the NMR-derived lipoprotein particle numbers and apolipoprotein concentrations than the LipoProfile® test commercialized by Liposcience. We also converted LDL particle numbers to ApoB equivalents (mg/dL) and our test yielded similar values of LDL-ApoB than the LipoProfile® test (absolute mean bias of 8.5 and 7.4 mg/dL, respectively). In addition, our HDL-P values were more concordant with the calibrated values determined recently using ion mobility. Finally, principal component analysis distinguished type 2 diabetic patients with and without atherogenic dyslipidemia (AD) on a second cohort of 307 subjects characterized using the Liposcale test (AUC=0.88) and showed concordant relationships between variables explaining AD. Altogether, our method provides reproducible and reliable characterization of lipoprotein particles and it is applicable to pathological states such as AD.
5 November 2014 in Analytical and Bioanalytical Chemistry
Polycystic ovary syndrome (PCOS) is a variable disorder characterized by a broad spectrum of anomalies, including hyperandrogenemia, insulin resistance, dyslipidemia, body adiposity, low-grade inflammation and increased cardiovascular disease risks. Recently, a new polytherapy consisting of low-dose flutamide, metformin and pioglitazone in combination with an estro-progestagen resulted in the regulation of endocrine clinical markers in young and non-obese PCOS women. However, the metabolic processes involved in this phenotypic amelioration remain unidentified. In this work, we used NMR and MS-based untargeted metabolomics to study serum samples of young non-obese PCOS women prior to and at the end of a 30 months polytherapy receiving low-dose flutamide, metformin and pioglitazone in combination with an estro-progestagen. Our results reveal that the treatment decreased the levels of oxidized LDL particles in serum, as well as downstream metabolic oxidation products of LDL particles such as 9- and 13-HODE, azelaic acid and glutaric acid. In contrast, the radiuses of small dense LDL and large HDL particles were substantially increased after the treatment. Clinical and endocrine-metabolic markers were also monitored, showing that the level of HDL cholesterol was increased after the treatment, whereas the level of androgens and the carotid intima-media thickness were reduced. Significantly, the abundance of azelaic acid and the carotid intima-media thickness resulted in a high degree of correlation. Altogether, our results reveal that this new polytherapy markedly reverts the oxidant status of untreated PCOS women, and potentially improves the pro-atherosclerosis condition in these patients.
Poor immunological recovery in treated HIV-infected patients is associated with greater morbidity and mortality. To date, predictive biomarkers of this incomplete immune reconstitution have not been established. We aimed to identify a baseline metabolomic signature associated with a poor immunological recovery after ART in order to envisage the underlying mechanistic pathways that influence the treatment response. This was a multi-centre, prospective cohort study in ART–naïve and a pre-ART low nadir (<200 cells/μl) HIV-infected patients (n = 64). We obtained clinical data and metabolomic profiles for each individual, in which low molecular weight metabolites, lipids and lipoproteins (including particle concentrations and sizes) were measured by nuclear magnetic resonance spectroscopy. Immunological recovery was defined as reaching CD4+ T-cell count ≥250 cells/μL after 36 months of virologically successful ART. We used univariate comparisons, Random Forest test and ROC curves to identify and evaluate the predictive factors of immunological recovery after treatment. HIV-infected patients with a baseline metabolic pattern characterized by high levels of large HDL particles, HDL cholesterol and larger sizes of LDL particles had a better immunological recovery after treatment. Conversely, patients with high ratios of non HDL lipoprotein particles did not experience this full recovery. Medium VLDL particles and glucose increased the classification power of the multivariate model despite not showing any significant differences between the two groups. In HIV-infected patients, a baseline healthier metabolomic profile is related to a better response to ART where the lipoprotein profile, mainly large HDL particles, may play a key role.
1 March 2016 in Clínica e Investigación en Arteriosclerosis