title: Insulin levels are decreased in the cerebrospinal fluid of women with prodomal Alzheimer's disease.
abstract: Previous studies have failed to reach consensus on insulin levels in cerebrospinal fluid of Alzheimer's disease (AD) patients and on its relation to pathological features. We performed a new analysis in patients at different stages of AD, and investigated the relationship of insulin levels with biochemical disease markers and with cognitive score. We included 99 patients from our Memory Clinic (Karolinska University Hospital, Sweden), including: 27 patients with mild AD, 13 that progressed from mild cognitive impairment (MCI) to AD in two years time, 26 with MCI stable after two years, and 33 with subjective cognitive impairment. Insulin was significantly decreased in the cerebrospinal fluid of both women and men with mild AD. Insulin deficits were seen in women belonging to both MCI groups, suggesting that this occurs earlier than in men. Insulin was positively associated with amyloid-β 1-42 (Aβ1-42) levels and cognitive score. Furthermore, total-tau/(Aβ1-42*insulin) ratio showed strikingly better sensitivity and specificity than the total-tau/Aβ1-42 ratio for early AD diagnosis in women.
authors.affiliation: Department of Neurobiology, Care Sciences and Society, Karolinska Institutet-Alzheimer's Disease Research Center, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Gil-Bea
authors.forename: Maite
authors.initials: M
authors.lastname: Solas
authors.forename: Alina
authors.initials: A
authors.lastname: Solomon
authors.forename: Carmen
authors.initials: C
authors.lastname: Mugueta
authors.forename: Bengt
authors.initials: B
authors.lastname: Winblad
authors.forename: Miia
authors.initials: M
authors.lastname: Kivipelto
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Ramirez
authors.forename: Angel
authors.initials: A
authors.lastname: Cedazo-Mínguez
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000134:cerebrospinal fluid*; D016229:Amyloid beta-Peptides / Q000134:cerebrospinal fluid; D000704:Analysis of Variance; D003072:Cognition Disorders / Q000134:cerebrospinal fluid*; D018450:Disease Progression; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D006801:Humans; D007328:Insulin / Q000134:cerebrospinal fluid*; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010446:Peptide Fragments / Q000134:cerebrospinal fluid; D012044:Regression Analysis; D012727:Sex Characteristics
chemical_list: D016229:Amyloid beta-Peptides; D007328:Insulin; D010446:Peptide Fragments; C075222:amyloid beta-protein (1-42)