Plasma acyl-carnitines, bilirubin, tyramine and tetrahydro-21-deoxycortisol in Parkinson's disease and essential tremor. A case control biomarker study.

BACKGROUND AND PURPOSE: Given the overlapping clinical manifestations and pathology, the differentiation between essential tremor (ET) and Parkinson's disease (PD) is difficult. Our aims were to examine the plasma metabolomics profiling and their association with motor and non-motor symptoms (NMS) in patients with PD, and to determine differences between de novo PD compared to moderate-advanced PD vs. controls and patients with ET. METHODS: Plasma samples were collected from 137 subjects including 35 age matched controls, 29 NOVO-PD, 35 PD and 38 ET patients. PD severity, motor and NMS including cognitive function were assessed using the UPDRS, NMS and PD cognitive rating scales, respectively. Metabolomics analysis was performed by UPLC-ESI-QToF-MS followed by unsupervised multivariate statistics. The area under the curve of the biomarkers according to distribution of their concentrations and the diagnosis of PD (NOVO-PD, advanced PD) vs ET and healthy controls was used as a measurement of diagnostic ability. RESULTS: Several acyl-carnitines, bilirubin, tyramine and tetrahydro-21-deoxycortisol (THS) presented good predictive accuracy (AUC higher than 0.8) for differentiating de novo PD and advanced PD from controls and ET, suggesting an alteration in the lipid oxidation pathway. In multivariate regression analysis, metabolite levels were not significantly associated with motor and NMS severity in PD. CONCLUSIONS: Diverse acyl-carnitines, bilirubin, tyramine and some adrenal gland derived metabolites are suggested as potential biomarkers able to distinguish between PD from controls and ET.

Lack of association between carotid intima-media thickness and apolipoprotein (a) isoforms in a sample of Spanish general population.

OBJECTIVES: The purpose of this study was to examine the relationship between apolipoprotein (a) isoforms and early atherosclerosis, assessed by carotid artery intima-media thickness in a sample of adults of the general population of Burgos, a city in the north of Spain. DESIGN AND METHODS: Lipids, lipoprotein (a), number of carotid atherosclerotic plaques, if any, and the intima-media thickness in the far wall of both common carotid arteries by B-mode ultrasound were determined in a group of 171 adults from the general population of Burgos, Spain. Apolipoprotein (a) isoforms were determined in a random subset of 119 subjects. RESULTS: Increasing age, male sex, and past personal cardiovascular history were significantly associated with increased left, right, or average intima-media thickness of both carotid arteries in multivariate analysis. No statistically significant association was found between apolipoprotein (a) isoforms and mean carotid intima-media thickness by bivariate or multivariate regression analysis. CONCLUSIONS: In this sample of the general Spanish population, no association was found between apolipoprotein (a) isoforms and carotid artery intima-media thickness.