title: Serum Levels of Acyl-Carnitines along the Continuum from Normal to Alzheimer's Dementia.
abstract: This study aimed to determine the serum levels of free L-carnitine, acetyl-L-carnitine and 34 acyl-L-carnitine in healthy subjects and in patients with or at risk of Alzheimer's disease. Twenty-nine patients with probable Alzheimer's disease, 18 with mild cognitive impairment of the amnestic type, 24 with subjective memory complaint and 46 healthy subjects were enrolled in the study, and the levels of carnitine and acyl-carnitines were measured by tandem mass spectrometry. The concentrations of acetyl-L-carnitine progressively decreased passing from healthy subjects group (mean±SD, 5.6±1.3 μmol/L) to subjective memory complaint (4.3±0.9 μmol/L), mild cognitive impairment (4.0±0.53 μmol/L), up to Alzheimer's disease (3.5±0.6 μmol/L) group (p<0.001). The differences were significant for the comparisons: healthy subjects vs. subjective memory complaint, mild cognitive impairment or Alzheimer's disease group; and subjective memory complaint vs. Alzheimer's disease group. Other acyl-carnitines, such as malonyl-, 3-hydroxyisovaleryl-, hexenoyl-, decanoyl-, dodecanoyl-, dodecenoyl-, myristoyl-, tetradecenoyl-, hexadecenoyl-, stearoyl-, oleyl- and linoleyl-L-carnitine, showed a similar decreasing trend, passing from healthy subjects to patients at risk of or with Alzheimer's disease. These results suggest that serum acetyl-L-carnitine and other acyl-L-carnitine levels decrease along the continuum from healthy subjects to subjective memory complaint and mild cognitive impairment subjects, up to patients with Alzheimer's disease, and that the metabolism of some acyl-carnitines is finely connected among them. These findings also suggest that the serum levels of acetyl-L-carnitine and other acyl-L-carnitines could help to identify the patients before the phenotype conversion to Alzheimer's disease and the patients who would benefit from the treatment with acetyl-L-carnitine. However, further validation on a larger number of samples in a longitudinal study is needed before application to clinical practice.
authors.affiliation: Centre for Research and Training in Medicine for Aging, Department of Medicine and Health Sciences "Vincenzo Tiberio", University of Molise, Campobasso, Italy.
authors.forename: Adriana
authors.initials: A
authors.lastname: Cristofano
authors.affiliation: Centre for Research and Training in Medicine for Aging, Department of Medicine and Health Sciences "Vincenzo Tiberio", University of Molise, Campobasso, Italy.
authors.forename: Nadia
authors.initials: N
authors.lastname: Sapere
authors.affiliation: Newborn Screening, Biochemistry and Pharmacology Laboratories, Clinic of Pediatric Neurology, Meyer University Children's Hospital, Florence, Italy.|Department of Neurosciences, Psychology, Pharmacology and Child Health, University of Florence, Florence, Italy.
authors.forename: Giancarlo
authors.initials: G
authors.lastname: La Marca
authors.affiliation: Centre for Research and Training in Medicine for Aging, Department of Medicine and Health Sciences "Vincenzo Tiberio", University of Molise, Campobasso, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Angiolillo
authors.affiliation: Centre for Research and Training in Medicine for Aging, Department of Medicine and Health Sciences "Vincenzo Tiberio", University of Molise, Campobasso, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Vitale
authors.affiliation: Centre for Research and Training in Medicine for Aging, Department of Medicine and Health Sciences "Vincenzo Tiberio", University of Molise, Campobasso, Italy.
authors.forename: Graziamaria
authors.initials: G
authors.lastname: Corbi
authors.affiliation: Centre for Research and Training in Medicine for Aging, Department of Medicine and Health Sciences "Vincenzo Tiberio", University of Molise, Campobasso, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Scapagnini
authors.affiliation: Centre for Research and Training in Medicine for Aging, Department of Medicine and Health Sciences "Vincenzo Tiberio", University of Molise, Campobasso, Italy.
authors.forename: Mariano
authors.initials: M
authors.lastname: Intrieri
authors.affiliation: Centre for Research and Training in Medicine for Aging, Department of Medicine and Health Sciences "Vincenzo Tiberio", University of Molise, Campobasso, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Russo
authors.affiliation: Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy.
authors.forename: Gaetano
authors.initials: G
authors.lastname: Corso
authors.affiliation: Centre for Research and Training in Medicine for Aging, Department of Medicine and Health Sciences "Vincenzo Tiberio", University of Molise, Campobasso, Italy.
authors.forename: Alfonso
authors.identifier: 0000-0002-6138-5640
authors.initials: A
authors.lastname: Di Costanzo
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000097:blood*; D000704:Analysis of Variance; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D002138:Calibration; D002331:Carnitine / Q000031:analogs & derivatives* / Q000097:blood; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000097:blood; D003704:Dementia / Q000097:blood*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D012306:Risk
chemical_list: D015415:Biomarkers; C116917:acylcarnitine; D002331:Carnitine